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