Close RadWindow on Escape Key Press

Hi , Here I will tell you that how to close RadWindow on Escape Key Press


 <script type="text/javascript">        
       document.onkeydown = function(evt)
       {
        evt = evt || window.event;
        if (evt.keyCode == 27) {
        var oWnd = $find("<%= RadWindow1.ClientID %>");
        oWnd.close();    
        }
       };

</script>

Thanks.