function MM_openBrWindow(theURL,winName,features) { //v2.0
    window.open(theURL,winName,features);
}

function openpopup(url){
    MM_openBrWindow(url, 'popup', 'toolbar=no,status=yes,scrollbars=yes,location=no,menubar=no,directories=no,resizable=no,width=645,height=500');
}