Field-Symbol Problem

D/A,

Please help me out in analyzing the root cause of the error appearing when i am trying to execute a module pool program.

Top Include :

constants cw_dokob type drad-dokob value 'ASMD'.

• Short Txt column on the Table control

DATA: W_DKTXT TYPE MCDOK-DKTXT.

• To store the dynpro column info

DATA: T_TAB TYPE TABLE OF CXTAB_COLUMN.

• to populate T_TAB at first run of this program

DATA: W_FIRST_RUN TYPE XFELD VALUE 'X'.

constants cw_dokob2 type drad-dokob value 'PLKO'.

MODULE call_object_pbo

FIELD-SYMBOLS <FS> TYPE ANY.

CLEAR W_DYNNR.

clear w_dokob.

• On first run of this program Store the Table control configuration

IF W_FIRST_RUN = 'X'.

CLEAR W_FIRST_RUN.

T_TAB[] = TAB_X1-COLS[].

ENDIF.

IF <FS> = cw_dokob.

W_DYNNR = '9001'.

W_DOKOB = CW_DOKOB.

ELSEIF <FS> = cw_dokob2.

W_DYNNR = '9002'.

W_DOKOB = CW_DOKOB2.

endmodule.

Thanx,

Akhil

when i m executing this piece of code,dump is being thrown with a reason that "Field symbol has not yet been assigned."