function pop(pop_url,win_name,w,h,sc) {
    var l = (screen.width  ? (screen.width - w) / 2 : 0);
    var t = (screen.height ? (screen.height - h) / 2 : 0);
    winhandle=window.open(pop_url,win_name,'width='+w+',left='+l+',height='+h+',top='+t+(sc ? ',scrollbars=yes,resizable=yes' : '')+',location=no,status=no,toolbar=no');
    winhandle.focus();
}