/*  

** Built-in:  DBMS_ERROR_CODE,DBMS_ERROR_TEXT 
** Example:   Reword certain Form Builder error messages by
**            evaluating the DBMS error code that caused them 
** Trigger:   On-Error 
*/ 
DECLARE 
  errcode     NUMBER        := ERROR_CODE; 
  dbmserrcode NUMBER; 
  dbmserrtext VARCHAR2( 200 ); 
BEGIN 
  IF errcode =  40508  THEN 
    /* 
    ** Form Builder had a problem INSERTing, so 
    ** look at the Database error which 
    ** caused the problem. 
    */ 
    dbmserrcode := DBMS_ERROR_CODE; 
    dbmserrtext := DBMS_ERROR_TEXT; 

    IF dbmserrcode = - 1438  THEN 
      /* 
      ** ORA-01438 is "value too large for column" 
      */ 
      Message('Your number is too large. Try again.'); 
    ELSIF dbmserrcode = - 1400  THEN 
      /* 
      ** ORA-01400 is "Mandatory column is NULL"
      */ 
      Message('You forgot to provide a value. Try again.'); 
    ELSE 
      /* 
      ** Printout a generic message with the database 
      ** error string in it. 
      */     
      Message('Insert failed because of '||dbmserrtext);
    END IF; 
  END IF; 
END;