This macro sets the checked state of the specified button control. It returns the previous check state.

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

HWND      hwndDlg;     /*  Dialog window handle. */
USHORT    usId;        /*  Button control identity. */
USHORT    usChkstate;  /*  Indicates the current checked state of the button. */
USHORT    usRetChkst;  /*  Returns the previous checkstate. */

usRetChkst = WinCheckButton(hwndDlg, usId,
               usChkstate);