function openCenteredWindow(url,width,height,name,parms) {
	var left = Math.floor((screen.width - width) / 2);
	var top = Math.floor((screen.height - height) / 2);
	var winParms = "top=" + top + ",left=" + left + ",height=" + height + ",width=" + width;
	if (parms) { winParms += "," + parms; }
	var win = window.open(url, name, winParms);
	if (parseInt(navigator.appVersion) >= 4) { win.window.focus(); }
	return win;
}