function popup(file,options,width,height)
{
	if ((width != 0 || width !=null) && (height != 0 || height !=  null))
		{
			var popLeft = (screen.width - width) / 2;
			var popTop = (screen.height - height) / 2;
			options = options+",width="+width+",height="+height+",left="+popLeft+",top="+popTop;
		}
	var textWindow=window.open(file,"TextWindow",options);
}