This function causes a pop-up menu to be presented.

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

HWND     hwndParent;  /*  Parent-window handle. */
HWND     hwndOwner;   /*  Owner-window handle. */
HWND     hwndMenu;    /*  Pop-up menu-window handle. */
LONG     x;           /*  x-coordinate of the pop-up menu position. */
LONG     y;           /*  y-coordinate of the pop-up menu position. */
LONG     idItem;      /*  Item identity. */
ULONG    fs;          /*  Options. */
BOOL     rc;          /*  Pop-up menu invoked indicator. */

rc = WinPopupMenu(hwndParent, hwndOwner, hwndMenu,
       x, y, idItem, fs);