Purchase requisition- Mat. description problem.

Question

Hi Experts,
I am stuck with one problem regarding Purchase requisition material description. The scenario is as follows.
We have two types of PR creation. With or without material code.
Material description is set to display only. But if the user enters the material code and random description and then press Enter button then the system doesnt pick the description from MAKT and keep the random description and disabling it for input. As shown in below screen shot.
I want to restrict this, So I used the enhancement - MEREQ001 in CMOD and exit - EXIT_SAPLMEREQ_010  and INCLUDE ZXM02U12 , to compare the material description and change it to master data from table MAKT. But the problem here is the original PR data fetched in to the exit is not changing. I have written below code.
+++++++++++++++++++++++++++++++++++++++++++++
LOOP AT im_t_eban INTO l_s_eban.
IF l_s_eban-matnr <> ''.
        SELECT SINGLE maktx FROM makt INTO mde
          WHERE matnr = l_s_eban-matnr.
          IF mde <> l_s_eban-txz01 .
            MESSAGE w007(zm_msg) . " DISPLAY LIKE 'E'.
            l_s_eban-txz01 = mde.
              MODIFY im_t_eban FROM l_s_eban TRANSPORTING txz01. " THIS LINE IS GIVING SYNTAX ERROR THAT im_t_eban is not changeable
          ENDIF.
      ENDIF.
ENDLOOP.
++++++++++++++++++++++++++++++++++++++
So how to solve this problem??
Or is there any other way to restrict the user to change the material description ??
Thanks,
Vishal .

Answer 1

hello abaper,
have a look on this
Hi Gaurav, try this:
http://scn.sap.com/thread/3297154
FIELD-SYMBOLS: <T_EBAN> type mereq_t_eban.
FIELD-SYMBOLS: <im_t_eban> type mereq_t_eban.
DATA: wa_eban LIKE eban.
ASSIGN ('(SAPLMEREQ)LT_EBAN[]') to  <T_EBAN> .   <-Uncommet this line
LOOP AT <im_t_eban> INTO wa_eban.
* => here you can change the value
   SELECT SINGLE matnr maktx into (mcode,mdesc)
         FROM makt
         WHERE matnr = wa_eban-matnr.
     if sy-subrc = 0 .
     move mdesc to wa_eban-txz01.
   MODIFY <T_EBAN> from wa_eban TRANSPORTING txz01.   <-Change the field-symbol for the one that is referencing the standard table
     ENDIF.
ENDLOOP.