This function indicates if the specified menu item is a valid choice.

#define INCL_WINWINDOWMGR /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HWND      hwndMenu;  /*  Menu window handle. */
USHORT    usId;      /*  Identity of the menu item. */
BOOL      rc;        /*  Validity indicator. */

rc = WinIsMenuItemValid(hwndMenu, usId);