This function creates a modal window, similar to WinMessageBox, that can be used to display error messages and ask questions.

#define INCL_SW
#include <os2.h>

HWND        hwndParent;  /*  Parent window handle. */
HWND        hwndOwner;   /*  Owner window handle. */
PSZ         pszText;     /*  Message text. */
PSZ         pszCaption;  /*  Title of secondary message box window. */
ULONG       idWindow;    /*  ID of window. */
PSMBINFO    psmbinfo;    /*  Information block. */
ULONG       rc;          /*  Results. */

rc = WinSecondaryMessageBox(hwndParent, hwndOwner,
       pszText, pszCaption, idWindow, psmbinfo);