function PopupWindow(url, height, width) 
{
	var win;
	var center = "";
	
	// Find left and top coordinates to center window
	if (navigator.appVersion.indexOf("MSIE") > -1 || (navigator.appName == "Netscape" && parseInt(navigator.appVersion.charAt(0)) >= 4)) {
		var h = (screen.availHeight - height) / 2;
		var w = (screen.availWidth - width) / 2;
		var center = ",top=" + h + ",left=" + w;
	}
		
	if (!win || win.closed)
	{
		win = window.open(url,"","resizable=yes,scrollbars=yes,toolbar=no,location=no,directories=no,status=yes,menubar=no,height=" + height + ",width=" + width + "" + center)
		if (!win.opener)
		{
			win.opener = window
		}
	} 
	else
	{
		// window's already open; bring to front
		win.focus()
	}
}