function pop( URL, x, y, scroll ) {
	popX=x;
	popY=y;
	posX=((screen.availWidth/2)-(popX/2));
	posY=((screen.availHeight/2)-(popX/2));
	
	window.open(URL,"Pagename","height="+popY+",width="+popX+",toolbar=0,menubar=0,directories=0,scrollbars="+scroll+",left="+posX+",top="+posY);
}