I had report..
After output is displayed i had put one push button on the application tool bar...
Once that button clicks it should call a screen.
I acheived this by calling a subscreen in a report as shown below.....
SELECTION-SCREEN BEGIN OF SCREEN 0101 AS SUBSCREEN.
SELECT-OPTIONS: material FOR mara-matnr.
PARAMETERS:kunnr TYPE kna1-kunnr .
SELECTION-SCREEN END OF SCREEN 0101.
I created a sub screen area in screen no 100 and wrote corresponding logic to handle subscreen..
If user did not enter kunnr and material i am throwing error message after displaying error message fields(material and kunr) are disabled..
I need to enable the fields of both material and kunnr after displaying error message so that user can enter again.
How to acheive this..