function openPopup(Url) {
 windowFeatures ="menubar=no,scrollbars=yes,location=no,favorites=no,resizable=no,status=no,toolbar=no,directories=no";
 width=600;
 height=400;
 // Centralize the popup window.
 winLeft = (screen.width-width)/2;
 winTop = (screen.height-(height+110))/2;
 window.open(Url, "popup", "width="+width+",height="+height+",left=" + winLeft + ",top=" + winTop + ","+windowFeatures);
}