11-23-2007 6:02 AM
hi guru's i am learning ,i am learning user exists , i don't know anything about that plz help me lie realtime oriented
11-23-2007 6:05 AM
Hi
USER EXIT
EXIT s are nothing but the R/3 Enhancements which allows you to add your own functionality to SAPs standard business applications without having to modify the original applications.
Purpose
To introduce the techniques of enhancement in standard SAP system. SAP creates customer exits for specific programs, screens, and menus within standard R/3 applications. These exits do not contain any functionality. Instead, the customer exits act as hooks. You can hang your own add-on functionality onto these hooks.
Use
They do not affect standard SAP source code.
When you add new functionality to your SAP System using SAPs exits, you do not alter the source code of standard SAP programs in any way. The code and screens you create are encapsulated as separate objects. These customer objects are linked to standard applications, but exist separately from SAPs standard software package.
They do not affect software updates.
When you add new functionality to your SAP System using SAPs exits, your objects (called customer objects) must adhere to strict naming conventions. When it comes time to upgrade a to a new software release, customer objects names ensure that they will not be affected by any changes or new additions to the standard software package.
Challenges
Customer exits are not available for all programs and screens found in the SAP System.
Modifications
Any change made to an SAP object in a customer system is called a modification. Customers usually modify their systems for one of two reasons. Either they make changes to the SAP standard in order to adjust the R/3 System to their specific business needs (actual modifications), or they alter individual SAP objects in order to correct an error (as recommended in an SAP error note).
You should only modify the SAP standard if the modifications you want to make are absolutely necessary for optimizing work flow in your company. Be aware that good background knowledge of application structure and flow are important prerequisites for deciding what kind of modifications to make and how these modifications should be designed.
need
ABAP DICTIONARY
Table Enhancements: There are two ways that you can add additional fields to tables without modifying your system.
Append Structures:
Append structures allow you to enhance tables by adding fields to them that are not part of the standard. With append structures, customers can add their own fields to any table or structure they want.
Append structures are created for use with a specific table. However, a table can have multiple append structures assigned to it.
Customizing Includes:
If customers know in advance that one of the tables or structures delivered to them by SAP needs to have customer-specific fields added to it, an SAP application developer can include these fields in the table using a Customizing include statement.
The same Customizing include can be used in multiple tables or structures. This provides for consistency in these tables and structures whenever the itself include is altered.
Append structures allow you to attach fields to a table without actually having to modify the table itself.
Append structures may only be assigned to a single table. A table may, however, have several append structures attached to it. Whenever a table is activated, the system searches for all active append structures for that table and attaches them to the table. If an append structure is created or changed and then activated, the table it is assigned to is also activated, and all of the changes made to the append structure take effect in the table as well.
You can use append structures in ABAP programs just as you would any other structure.
Note: When you copy tables that have append structures attached to them, the fields that were found in the append structure of the original table become part of the actual body of the target table.
Some of the tables and structures delivered with the R/3 standard contain special include statements calling Customizing includes. These are often inserted in those standard tables that need to have customer-specific fields added to them.
In contrast to append structures, Customizing includes can be inserted into more than one table. This provides for data consistency throughout the tables and structures affected whenever the include is altered.
Customizing include programs are part of the customer namespace: all of their names begin with 'CI_'. This naming convention guarantees that nonexistent Customizing includes do not lead to errors. No code for Customizing includes is delivered with the R/3 standard.
You create Customizing includes using special Customizing transactions. Some are already part of SAP enhancements and can be created by using project management (see the unit on 'Enhancements using Customer Exits').
The Customizing include field names must lie in the customer namespace just like field names in append structures. These names must all begin with either 'YY' or 'ZZ'.
When adding the fields of a Customizing include to your database, adhere to same rules you would with append structures.
ABAP DICTIONARY
Field Exits:
Field exits take you from a screen field with a data element reference to a function module. Field exits can be either global or local.
Field exit function modules adhere to the following naming convention:
prefix: FIELD_EXIT_
name: <data element name>_
suffix (optional): 0 to 9, A to Z
Text Enhancements:
Possible text enhancements include customer keywords and customer documentation of data elements.
Text enhancements differ from other application enhancements in that they take effect globally in all related SAP applications after activation (global enhancements).
Customer Exits
Function Module Exits
Menu Exits
Screen Exits
Function Module Exits
Function module exits add functions to R/3 applications. Function module exits play a role in both menu and screen exits. When you add a new menu item to a standard pull down menu, you use a function module exit to define the actions that should take place once your menu is activated. Function module exits also control the data flow between standard programs and screen exit fields.
Menu Exits
Menu exits add items to the pull down menus in standard SAP applications. You can use these menu items to call up your own screens or to trigger entire add-on applications.
SAP creates menu exits by defining special menu items in the Menu Painter. These special entries have function codes that begin with "+" (a plus sign). You specify the menu items text when activating the item in an add-on project.
Screen Exits
Screen exits add fields to screens in R/3 applications. SAP creates screen exits by placing special sub screen areas on a standard R/3 screen and calling a customer sub screen from the standard screens flow logic.
Exits are basically the hooks whcih SAP has provided to add your own code. There are two types of Exits:
1. Customer exits: Implemented as Function Modules within z includes. Anybody can change it and no access key is required.
2. User Exit: Implemented as subroutines within includes (any include except y or z includes). You need access for the specific include and then you can any subroutine (user exit) within that Include.
BADIs are the enhanced version of user exits where the same logic is implemented via classes and object (OOP)
Enchancement point is the latest once introduces with ECC6.0 . Not very sure about that but you can change it without any access key.
Please go through the following link which will help you understand the exits in a much better way:
http://help.sap.com/saphelp_nw04/helpdata/en/bf/ec07a25db911d295ae0000e82de14a/content.htm
http://www.sap-img.com/abap/what-is-the-difference-between-smod-and-cmod.htm
http://sap.niraj.tripod.com/id21.html
http://help.sap.com/saphelp_nw04/helpdata/en/c8/1975cc43b111d1896f0000e8322d00/frameset.htm
http://www.sap-img.com/ab038.htm
User Exits.
-
http://www.erpgenie.com/sap/abap/code/abap26.htm
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sapgenie.com/abap/code/abap26.htm
http://www.sap-img.com/abap/what-is-user-exits.htm
http://wiki.ittoolbox.com/index.php/HOWTO:Implement_a_screen_exit_to_a_standard_SAP_transaction
http://www.easymarketplace.de/userexit.php
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sappoint.com/abap/userexit.pdfUser-Exit
customer exits
Menu Exit.
http://www.sappoint.com/abap/spmp.pdf
http://www.sappoint.com/abap/userexit.pdf
http://www.sapdevelopment.co.uk/enhance/mod_sapmenu.htm
http://www.sapdevelopment.co.uk/enhance/enhancehome.htm
USER EXIT
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sapgenie.com/abap/code/abap26.htm
http://www.sap-img.com/abap/what-is-user-exits.htm
http://wiki.ittoolbox.com/index.php/HOWTO:Implement_a_screen_exit_to_a_standard_SAP_transaction
http://www.easymarketplace.de/userexit.php
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sappoint.com/abap/userexit.pdfUser-Exit
http://www.sap-img.com/ab038.htm
http://help.sap.com/saphelp_46c/helpdata/en/64/72369adc56d11195100060b03c6b76/frameset.htm
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sap-img.com/abap/what-is-user-exits.htm
http://expertanswercenter.techtarget.com/eac/knowledgebaseAnswer/0,295199,sid63_gci982756,00.html
11-23-2007 6:05 AM
Hi
USER EXIT
EXIT s are nothing but the R/3 Enhancements which allows you to add your own functionality to SAPs standard business applications without having to modify the original applications.
Purpose
To introduce the techniques of enhancement in standard SAP system. SAP creates customer exits for specific programs, screens, and menus within standard R/3 applications. These exits do not contain any functionality. Instead, the customer exits act as hooks. You can hang your own add-on functionality onto these hooks.
Use
They do not affect standard SAP source code.
When you add new functionality to your SAP System using SAPs exits, you do not alter the source code of standard SAP programs in any way. The code and screens you create are encapsulated as separate objects. These customer objects are linked to standard applications, but exist separately from SAPs standard software package.
They do not affect software updates.
When you add new functionality to your SAP System using SAPs exits, your objects (called customer objects) must adhere to strict naming conventions. When it comes time to upgrade a to a new software release, customer objects names ensure that they will not be affected by any changes or new additions to the standard software package.
Challenges
Customer exits are not available for all programs and screens found in the SAP System.
Modifications
Any change made to an SAP object in a customer system is called a modification. Customers usually modify their systems for one of two reasons. Either they make changes to the SAP standard in order to adjust the R/3 System to their specific business needs (actual modifications), or they alter individual SAP objects in order to correct an error (as recommended in an SAP error note).
You should only modify the SAP standard if the modifications you want to make are absolutely necessary for optimizing work flow in your company. Be aware that good background knowledge of application structure and flow are important prerequisites for deciding what kind of modifications to make and how these modifications should be designed.
need
ABAP DICTIONARY
Table Enhancements: There are two ways that you can add additional fields to tables without modifying your system.
Append Structures:
Append structures allow you to enhance tables by adding fields to them that are not part of the standard. With append structures, customers can add their own fields to any table or structure they want.
Append structures are created for use with a specific table. However, a table can have multiple append structures assigned to it.
Customizing Includes:
If customers know in advance that one of the tables or structures delivered to them by SAP needs to have customer-specific fields added to it, an SAP application developer can include these fields in the table using a Customizing include statement.
The same Customizing include can be used in multiple tables or structures. This provides for consistency in these tables and structures whenever the itself include is altered.
Append structures allow you to attach fields to a table without actually having to modify the table itself.
Append structures may only be assigned to a single table. A table may, however, have several append structures attached to it. Whenever a table is activated, the system searches for all active append structures for that table and attaches them to the table. If an append structure is created or changed and then activated, the table it is assigned to is also activated, and all of the changes made to the append structure take effect in the table as well.
You can use append structures in ABAP programs just as you would any other structure.
Note: When you copy tables that have append structures attached to them, the fields that were found in the append structure of the original table become part of the actual body of the target table.
Some of the tables and structures delivered with the R/3 standard contain special include statements calling Customizing includes. These are often inserted in those standard tables that need to have customer-specific fields added to them.
In contrast to append structures, Customizing includes can be inserted into more than one table. This provides for data consistency throughout the tables and structures affected whenever the include is altered.
Customizing include programs are part of the customer namespace: all of their names begin with 'CI_'. This naming convention guarantees that nonexistent Customizing includes do not lead to errors. No code for Customizing includes is delivered with the R/3 standard.
You create Customizing includes using special Customizing transactions. Some are already part of SAP enhancements and can be created by using project management (see the unit on 'Enhancements using Customer Exits').
The Customizing include field names must lie in the customer namespace just like field names in append structures. These names must all begin with either 'YY' or 'ZZ'.
When adding the fields of a Customizing include to your database, adhere to same rules you would with append structures.
ABAP DICTIONARY
Field Exits:
Field exits take you from a screen field with a data element reference to a function module. Field exits can be either global or local.
Field exit function modules adhere to the following naming convention:
prefix: FIELD_EXIT_
name: <data element name>_
suffix (optional): 0 to 9, A to Z
Text Enhancements:
Possible text enhancements include customer keywords and customer documentation of data elements.
Text enhancements differ from other application enhancements in that they take effect globally in all related SAP applications after activation (global enhancements).
Customer Exits
Function Module Exits
Menu Exits
Screen Exits
Function Module Exits
Function module exits add functions to R/3 applications. Function module exits play a role in both menu and screen exits. When you add a new menu item to a standard pull down menu, you use a function module exit to define the actions that should take place once your menu is activated. Function module exits also control the data flow between standard programs and screen exit fields.
Menu Exits
Menu exits add items to the pull down menus in standard SAP applications. You can use these menu items to call up your own screens or to trigger entire add-on applications.
SAP creates menu exits by defining special menu items in the Menu Painter. These special entries have function codes that begin with "+" (a plus sign). You specify the menu items text when activating the item in an add-on project.
Screen Exits
Screen exits add fields to screens in R/3 applications. SAP creates screen exits by placing special sub screen areas on a standard R/3 screen and calling a customer sub screen from the standard screens flow logic.
Exits are basically the hooks whcih SAP has provided to add your own code. There are two types of Exits:
1. Customer exits: Implemented as Function Modules within z includes. Anybody can change it and no access key is required.
2. User Exit: Implemented as subroutines within includes (any include except y or z includes). You need access for the specific include and then you can any subroutine (user exit) within that Include.
BADIs are the enhanced version of user exits where the same logic is implemented via classes and object (OOP)
Enchancement point is the latest once introduces with ECC6.0 . Not very sure about that but you can change it without any access key.
Please go through the following link which will help you understand the exits in a much better way:
http://help.sap.com/saphelp_nw04/helpdata/en/bf/ec07a25db911d295ae0000e82de14a/content.htm
http://www.sap-img.com/abap/what-is-the-difference-between-smod-and-cmod.htm
http://sap.niraj.tripod.com/id21.html
http://help.sap.com/saphelp_nw04/helpdata/en/c8/1975cc43b111d1896f0000e8322d00/frameset.htm
http://www.sap-img.com/ab038.htm
User Exits.
-
http://www.erpgenie.com/sap/abap/code/abap26.htm
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sapgenie.com/abap/code/abap26.htm
http://www.sap-img.com/abap/what-is-user-exits.htm
http://wiki.ittoolbox.com/index.php/HOWTO:Implement_a_screen_exit_to_a_standard_SAP_transaction
http://www.easymarketplace.de/userexit.php
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sappoint.com/abap/userexit.pdfUser-Exit
customer exits
Menu Exit.
http://www.sappoint.com/abap/spmp.pdf
http://www.sappoint.com/abap/userexit.pdf
http://www.sapdevelopment.co.uk/enhance/mod_sapmenu.htm
http://www.sapdevelopment.co.uk/enhance/enhancehome.htm
USER EXIT
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sapgenie.com/abap/code/abap26.htm
http://www.sap-img.com/abap/what-is-user-exits.htm
http://wiki.ittoolbox.com/index.php/HOWTO:Implement_a_screen_exit_to_a_standard_SAP_transaction
http://www.easymarketplace.de/userexit.php
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sappoint.com/abap/userexit.pdfUser-Exit
http://www.sap-img.com/ab038.htm
http://help.sap.com/saphelp_46c/helpdata/en/64/72369adc56d11195100060b03c6b76/frameset.htm
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.sap-img.com/abap/what-is-user-exits.htm
http://expertanswercenter.techtarget.com/eac/knowledgebaseAnswer/0,295199,sid63_gci982756,00.html
11-23-2007 6:07 AM
Please check this links which will help you to know more detail on user exits.
http://sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://sap-img.com/abap/what-is-user-exits.htm
http://sap-img.com/abap/what-is-the-difference-between-smod-and-cmod.htm
http://help.sap.com/saphelp_nw04/helpdata/en/c8/1978b543b111d1896f0000e8322d00/frameset.htm
You can go to tcodes CMod and SMod for user exits.
:http://help.sap.com/saphelp_bw31/helpdata/en/35/26b334afab52b9e10000009b38f974/content.htm
http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm
http://www.planetsap.com/Userexit_List.htm
User exit to find out for particular transaction,use below code...
&----
*& Report ZSHW_USEREXIT *
*& *
&----
*& *
*& *
&----
*REPORT ZSHW_USEREXIT.
Finding the user-exits of a SAP transaction code
*
Enter the transaction code in which you are looking for the user-exit
and it will list you the list of user-exits in the transaction code.
Also a drill down is possible which will help you to branch to SMOD.
*
Written by : SAP Basis, ABAP Programming and Other IMG Stuff
*
report zuserexit no standard page heading.
tables : tstc, tadir, modsapt, modact, trdir, tfdir, enlfdir.
tables : tstct.
data : jtab like tadir occurs 0 with header line.
data : field1(30).
data : v_devclass like tadir-devclass.
parameters : p_tcode like tstc-tcode obligatory.
select single * from tstc where tcode eq p_tcode.
if sy-subrc eq 0.
select single * from tadir where pgmid = 'R3TR'
and object = 'PROG'
and obj_name = tstc-pgmna.
move : tadir-devclass to v_devclass.
if sy-subrc ne 0.
select single * from trdir where name = tstc-pgmna.
if trdir-subc eq 'F'.
select single * from tfdir where pname = tstc-pgmna.
select single * from enlfdir where funcname =
tfdir-funcname.
select single * from tadir where pgmid = 'R3TR'
and object = 'FUGR'
and obj_name eq enlfdir-area.
move : tadir-devclass to v_devclass.
endif.
endif.
select * from tadir into table jtab
where pgmid = 'R3TR'
and object = 'SMOD'
and devclass = v_devclass.
select single * from tstct where sprsl eq sy-langu and
tcode eq p_tcode.
format color col_positive intensified off.
write:/(19) 'Transaction Code - ',
20(20) p_tcode,
45(50) tstct-ttext.
skip.
if not jtab[] is initial.
write:/(95) sy-uline.
format color col_heading intensified on.
write:/1 sy-vline,
2 'Exit Name',
21 sy-vline ,
22 'Description',
95 sy-vline.
write:/(95) sy-uline.
loop at jtab.
select single * from modsapt
where sprsl = sy-langu and
name = jtab-obj_name.
format color col_normal intensified off.
write:/1 sy-vline,
2 jtab-obj_name hotspot on,
21 sy-vline ,
22 modsapt-modtext,
95 sy-vline.
endloop.
write:/(95) sy-uline.
describe table jtab.
skip.
format color col_total intensified on.
write:/ 'No of Exits:' , sy-tfill.
else.
format color col_negative intensified on.
write:/(95) 'No User Exit exists'.
endif.
else.
format color col_negative intensified on.
write:/(95) 'Transaction Code Does Not Exist'.
endif.
at line-selection.
get cursor field field1.
check field1(4) eq 'JTAB'.
set parameter id 'MON' field sy-lisel+1(10).
call transaction 'SMOD' and skip first screen.
*---End of Program
/people/ajay.das/blog/2005/03/28/custom-fields-and-bw-extractors-making-a-mixed-marriage-work-part-1-1
/people/ajay.das/blog/2005/03/28/custom-fields-in-standard-extractors--making-a-mixed-marriage-work--part-12
/people/sap.user72/blog/2005/02/14/logistic-cockpit--when-you-need-more--first-option-enhance-it
Reward Points if it is helpful.
11-23-2007 6:09 AM
Hi,
User exits are used for enhancing SAP standard functionality. For example if you want to have a user specific checking before saving a document, you can use the user exit.
For more information please check the following sites
http://www.planetsap.com/userexit_main_page.htm
http://www.sap-img.com/ab038.htm
BADI is another type of user exit. Check here for more information
http://www.sap-img.com/abap/difference-between-badi-and-user-exits.htm
http://expertanswercenter.techtarget.com/eac/knowledgebaseAnswer/0,295199,sid63_gci982776,00.html
To find user exit for a transaction code
http://www.sapgenie.com/abap/code/abap26.htm
reagrds,
Omkar.
11-23-2007 9:02 AM
Hi sri vasu ,
User exits :
1. Introduction:
User exits (Function module exits) are exits developed by SAP. The exit is implementerd as a call to a functionmodule. The code for the function module is writeen by the developer. You are not writing the code directly in the function module, but in the include that is implemented in the function module.
The naming standard of function modules for functionmodule exits is:
EXIT_<program name><3 digit suffix>
The call to a functionmodule exit is implemented as:
CALL CUSTOMER.-FUNCTION ❤️ digit suffix>
Example:
The program for transaction VA01 Create salesorder is SAPMV45A
If you search for CALL CUSTOMER-FUNCTION i program
SAPMV45A you will find ( Among other user exits):
CALL CUSTOMER-FUNCTION '003'
exporting
xvbak = vbak
xvbuk = vbuk
xkomk = tkomk
importing
lvf_subrc = lvf_subrc
tables
xvbfa = xvbfa
xvbap = xvbap
xvbup = xvbup.
The exit calls function module EXIT_SAPMV45A_003
2. How to find user exits?
Display the program where you are searching for and exit and search for CALL CUSTOMER-EXIT
If you know the Exit name, go to transaction CMOD.
Choose menu Utillities->SAP Enhancements. Enter the exit name and press enter.
You will now come to a screen that shows the function module exits for the exit.
3. Using Project management of SAP Enhancements, we want to create a project to enahance trasnaction VA01 .
- Go to transaction CMOD
- Create a project called ZVA01
- Choose the Enhancement assign radio button and press the Change button
In the first column enter V45A0002 Predefine sold-to party in sales document.
Note that an enhancement can only be used in 1 project. If the enhancement is already in use, and error message will be displayed
Press Save
Press Components. You can now see that enhancement uses user exit EXIT_SAPMV45A_002. Double click on the exit.
Now the function module is displayed. Double click on include ZXVVAU04 in the function module
Insert the following code into the include: E_KUNNR = '2155'.
Activate the include program. Go back to CMOD and activate the project.
Goto transaction VA01 and craete a salesorder.
Note that Sold-to-party now automatically is "2155"
User exit - A user exit is a three character code that instructs the system to access a program during system processing.
SXX: S is for standard exits that are delivered by SAP. XX represents the 2-digit exit number.
UXX: U is for user exits that are defined by the user. XX represents the 2-digit exit number
An example of a user exits :-
MODULE user_exit_0001 INPUT
CASE okcode.
WHEN 'BACK OR EXIT'.
CASE sy-dynnr.
WHEN '100'.
SET SCREEN 0.
LEAVE SCREEN.
WHEN '200'.
Note that you can write any code that satisfy your needs. ****
But in this case, this was wrote as a sample code for reference sake. ****
And you can test it. ****
SET SCREEN 100.
LEAVE SCREEN.
ENDCASE.
ENDCASE.
Finding User Exits
Procdedure 1:
Valid up to at least SAP release 4.0B
One way to find user exits applicable for a given SAP screen. From the SE38 screen, enter the desired screen main program, and click Utilities > Find In Source Code, and "CUSTOMER-FUNCTION" as the text to search for. This will give you a list of the user exits and where they are called from for all screens in the module pool.
Note: format of ABAP statement is CALL CUSTOMER-FUNCTION '009', for example. This is the statement called by a submodule attached to the main program.
Actual related function is EXIT_SAPLCOIH_009, for example. This example refers to customer function 9 in main program SAPLCOIH. Not all user exit functions are names as such, but this is the usual format.
If you are doing data validation and want to set an error message with a field open, you must be sure that the user exit you are using is linked to a calling module in the PAI section of the screen and the field you wish to be open was in the CHAIN statement which caused the PAI module to be invoked.
If you use a customer function which was invoked by a PBO module to validate data, the "MESSAGE" statement will cause the screen to return with the desired message at the bottom, but with all screen fields closed for input.
When you make changes to the include module for a given customer function, you must regenerate the related function group before you will see the changes included in the screen behaviour.
Procdedure 2:
Need to find user exits module-wise? Suppose we want to see the available sales module user exits. Go to transaction SE81. Click on SD, then click "edit" on the menu bar and choose select subtree. Click on "information system," Open Environment node, customer exits, and enhancements. Press F8 to get all the user exits for that module. In brief: SE81->SD->Select subtree->Information System->Envir->Exit Techniques->Customers exits->enhancements->Execute(F8)
USER EXIT (SAP Enhancement)
http://www.planetsap.com/userexit_det_1.htm
List of all USER EXIT's (4.6c version)
http://www.planetsap.com/Userexit_List.htm
User Exits in FI/CO
http://www.ficoexpertonline.com/downloads/User%20ExitsWPedit.doc
Excellent web-site for user-exits
http://www.abaptalk.com/forum_posts.asp?TID=31&SID=3b18fa1dc8b7b9a1dbdedf36fe3bc2az&PID=56#56
Enhancements,Creating a project,Assigning SAP enhancements to a project,Editing enhancement components,Activating a project
http://www.planetsap.com/userexit_main_page.htm
Find user exits with a TCode
http://www.erpgenie.com/abap/code/abap26.htm
SAP User Exits Routine
http://www.sap-basis-abap.com/sapab013.htm
User Exit and Enhancement explained in detail .
http://sap.niraj.tripod.com/id21.html
Excellent web-site for user-exits
http://www.abaptalk.com/forum_posts.asp?TID=31&SID=3b18fa1dc8b7b9a1dbdedf36fe3bc2az&PID=56#56
http://abap4.tripod.com/Other_Useful_Tips.html
cheers!
gyanaraj
****Pls reward points if u find this helpful