var ie=Boolean(document.all);
var ns4=Boolean(document.layers && !document.getElementById);
var gecko=Boolean(!document.all && document.getElementById);

function disableclick(e){
	if (ns4){
		if (e.which == 3) return false;
	}
	else if (gecko){
		if (e.button==2){
			e.cancelBubble=true;
			e.stopPropagation();
			e.preventDefault();
			return false;
		}
	}
}

if (ie) document.oncontextmenu=function(){
	return false;
}
else if (ns4){
	document.onmousedown=disableclick
	if (ns4) document.captureEvents(Event.MOUSEDOWN);
}
else{
	document.addEventListener('click',disableclick,false)
	document.addEventListener('dblclick',disableclick,false)
}