function popup(url, width, height) {
	var left = (screen.width - width)/2;
	var top = (screen.height - height)/2;
	newwindow=window.open(url,'services','toolbar=no,location=no,status=no,width=' + width + ',height=' + height + ',left=' + left + ',top=' + top + ',resizable=0,menubar=0,scrollbars=yes');
}