document.onkeydown=KeyEventHandle; 
document.onkeyup=KeyEventHandle; 
function KeyEventHandle() 
{ 
	if((event.ctrlKey == true && (event.keyCode == 78 || event.keyCode == 82)) || (event.keyCode >= 112 && event.keyCode <= 123)) 
		{ 
			event.keyCode		= 0; 
			event.cancelBubble	= true; 
			event.returnValue	= false; 
		} 
}