function openCentered(theURL,winName,winWidth,winHeight,features) {
	var w = (screen.width - winWidth)/2;
	var h = (screen.height - winHeight)/2 - 30;
	features = features+',width='+winWidth+',height='+winHeight+',top='+h+',left='+w;
	window.open(theURL,winName,features); 
}