function popup(mypage, myname, w, h, scroll, resizable, menubar) {
   var winl = (screen.width - w) / 2;
   var wint = (screen.height - h) / 2;
   winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars='+scroll+',resizable='+resizable+',menubar='+menubar+''
   win = window.open(mypage, myname, winprops)
   if (parseInt(navigator.appVersion) >= 4) win.window.focus();
}