function popCentered(url,widthVar,heightVar,windowName){
	var Xpos= (screen.availWidth - widthVar)/2;
	var Ypos= (screen.availHeight - heightVar)/2;
	var str="toolbar=no,location=no,scrollbars=yes,directories=no,status=no,menubar=no,resizable=no,copyhistory=no,left=" + Xpos + ",screenX=" + Xpos + ",top=" + Ypos + ",screenY=" + Ypos + ",width="+widthVar+",innerWidth="+widthVar+",height="+heightVar+",innerHeight="+heightVar;
	windowName = windowName == null ? "newWin" : windowName;
	window.open(url,windowName,str);}