WinSendMsg (SysMenu_window, MM_SETITEMATTR,                            
                            MPFROM2SHORT (                             
                                           SC_CLOSE,                   
                                           INCLUDE_SUBMENUS            
                                         ),                            
                            MPFROM2SHORT (                             
                                           MIA_DISABLED,               
                                           MIA_DISABLED_OFF
                                         ));
