Problem:

Solution:

Assembler DOM Subroutine
Sent by Joćo Reginato, Brazil
It should be used after calling WTO2 sub-program, once it uses the DOM-ID returned by it. This is the version that uses the full MVS linkage convention for non-reentrant assembler programs. I think it works fine for VSE too.

***********************************************************************
*                                                                     *
*        SUBROUTINE  : DOM (DELETE OPERATOR MESSAGE)                  *
*                      PREVIOUSLLY ISSUED WITH WTO DESC=2             *
*        RESTRICTION : THE DOM-ID SHOULD BE RETURNED BY WTO2 SUB-PGM  *
*        AUTHOR      : JOAO REGINATO - CPFL-1992/JUNE                 *
*                                                                     *
*        HOW TO CALL (COBOL SAMPLE)                                   *
*        --------------------------                                   *
*        01  MSG-DOM PIC S9(8) COMP.                                  *
*        CALL 'DOM' USING MSG-DOM.                                    *
*                                                                     *
*        HOW TO CALL (NATURAL SAMPLE)                                 *
*        ----------------------------                                 *
*        01  MSG-DOM B(4).                                            *
*        CALL 'DOM' MSG-DOM.                                          *
***********************************************************************
DOM      CSECT                             CSECT
         SAVE  (14,12),,DOM-&SYSDATE-&SYSTIME START AND IDENTIFY
         LR    12,15                       LOAD BASE REGISTER
         USING DOM,12                      ESTABLISH ADDRESSABILITY
         BAL   1,START                     BR AROUND SAVE AREA
         DS    18F                         NEW SAVE AREA
START    ST    13,4(,1)                    SAVE OLD SAVE AREA
         ST    1,8(,13)                    SAVE NEW SAVE AREA
         LR    14,13                       POINT OLD SAVE AREA
         LR    13,1                        POINT NEW SAVE AREA
         L     1,24(,14)                   LOAD CALLER PARM ADDRESS
         L     1,0(,1)                     LOAD DOM ID
         DOM   MSG=(1)                     DELETE MESSAGE FROM CONSOLE
         L     13,4(,13)                   LOAD TOLD SAVE AREA
         RETURN (14,12),RC=(15)            RETURN TO CALLER W/ DOM R15
         END

See also how to create non-scrolling WTO messages by using WTO assembler macro (WTO2 sub-program).