newWindow = new Object;
newWindow.closed = true;
function newWindowopener(open_url, w, h)
{
 tempvar = navigator.appVersion.substring(0,1);
 browser = parseInt(tempvar);
 if (browser < 3) {
   return true;
   } else {

  if (!newWindow.closed) {
     newWindow.close();
    }

 // Determine Center of work area

  var h_screen = screen.availHeight;
  var w_screen = screen.availWidth;

  var winl = (w_screen - w) / 2;
  var wint = (h_screen - h) / 2;

  winops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars=no,resizable=no,toolbar=no';

  win = window.open(open_url,"", winops);

if (browser >= 4)
   { win.window.focus(); }

  return false;
  }
 return true;
}