I have a module pool program, in that i have to set validation.

There is a field service order whenever user will enter service order number it should match with

ekko's ebeln if it doesn't then a message should come(enter correct serv order number)..how can i set validation on this??

I tried this in PAI..

when 'ENTER'.

if wa_data-sn1 = ekko-ebeln.
             wa_data-sn1 = wa_data-sn1.
          ELSE.
    MESSAGE 'Enter Correct Serivce Order Number' TYPE 'E'.
   ENDIF.

when i i am entering wright serv order no. then also it is showing error and for wrong also.

here wa_data-sn1(serv order number) is I/O text field.

what to do??