Upon completion of the above tasks, the begin function returns to VTAM®. It is not executed again until VTAM is reinitialized or until the exit is reinitialized following use of the MODIFY EXIT command (see z/OS Communications Server: SNA Operation for information about using this command to activate, deactivate, or replace certain installation-wide exit routines). The code that performs the return to VTAM must free the storage used as the register save area for the session management exit routine, reestablish the registers for VTAM, and ensure the return is properly set. All function routines can use the following code to exit to VTAM.    

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*
** RETURN TO VTAM
*
RETURN   EQU   *
         L     R2,4(R13)      RELOAD VTAM'S REGISTER SAVE AREA ADDRESS
         ST    R15,16(R2)     SET SME FUNCTION RETURN CODE IN VTAM'S
*                             REGISTER 15
         FREEMAIN R,LV=72,A=(R13) FREE REGISTER SAVE AREA STORAGE
         LR    R13,R2     RESET REGISTER 13 TO VTAM'S SAVE AREA ADDRESS
         LM    R14,R12,12(R13)  RESTORE VTAM'S REGISTERS
         BR    R14              EXIT TO VTAM
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