/**********************************************************************/
/*                                                                    */
/*    Assume you are currently editing data set MY.DATA using the     */
/*    FSEDIT procedure. You have a unique index on numeric variable   */
/*    JOBNUM and want to check for a duplicate value as soon as       */
/*    users enter a value for JOBNUM and press ENTER. The             */
/*    following SCL program provides this information:                */
/*                                                                    */
/**********************************************************************/ 
   FSEINIT:
      dsid=open('my.data','i');
   return;

   INIT:
      initial=jobnum;
   return;

   MAIN:
      if modified(jobnum) and jobnum ne initial then
         do;
            rc=where(dsid,'jobnum ='||put(jobnum,3.));
            any=attrn(dsid,'any');
            if any>0 then
               do;
                  erroron jobnum;
                  _msg_='You entered a duplicate value for JOBNUM';
               end;
         end;
   return;

   TERM:
   return;

   FSETERM:
      if (dsid>0) then rc=close(dsid);
   return;