How to display custom Message in RSRT and AO until valid input is given

[vijay_k1]

Hi Experts,

I have implemented BADI for customer exit variables - calling external program to implement form - endform.  I need to display a Message in RSRT and AO [Analysis for Office] until valid currency type value is given as input. It should allow to enter correct currency type value if wrong input is provided

In the called external called program in Form - endform - under i_step =3 , i have implemented the following code to display message. But I need to display my own custom message.

          TRY.
              IF lv_return_msg IS NOT INITIAL.
                RAISE EXCEPTION TYPE cx_rs_error_with_message
*                  MESSAGE ID 'BRAIN' TYPE 'W' NUMBER '655' WITH 'Enter Currency Type --> 30 '.
                exporting
                  msgid           = 'BRAIN'
                  msgno           = '642'
                  msgty           = sy-msgty
                  attribute_msgv1 = 'Currency Type.'.
              ENDIF. " lv_return_msg IS NOT INITIAL.
            CATCH cx_rs_error_with_message.
              MESSAGE ID 'BRAIN' TYPE 'W' NUMBER '642' WITH ' Currency Type.'.
          ENDTRY.

Please suggest me , is there any class available to display message (in both RSRT and AO) until valid currency type value is provided.

Thanks
kv