// Æã¼ÇÅ° ¸·±â
function processKey()
{
if( (event.ctrlKey == true && (event.keyCode == 78 || event.keyCode == 82 )) ||
        (event.keyCode >= 112 && event.keyCode <= 123) || (event.keyCode == 27))
    	{
        // alert(event.keyCode);
        event.keyCode = 0;
        event.cancelBubble = true;
        event.returnValue = false;
    	}	
}

document.onkeydown = processKey;