This example cancels a shutdown request (WM_QUIT message) and specifies that the message queue will not accept any new WM_QUIT messages.

#define INCL_WINMESSAGEMGR  /* Window Message Functions */
#include <os2.h>

HAB   hab,
BOOL  fSuccess;             /* Success indicator        */
HMQ   hmq;                  /* Queue handle             */

hmq      = WinCreateMsgQueue(hab, 0);
fSuccess = WinCancelShutdown(hmq, TRUE);