function popup_poll(sURL, sWindow, nWidth, nHeight)
{
   var hWindow;
   var sParams = "";

   // Standard modal arguments

   sParams += "resizable=yes";
   sParams += ",scrollbars=yes";
   sParams += ",location=no";
   sParams += ",toolbar=no";
   sParams += ",statusbar=no";
   sParams += ",width="+nWidth;
   sParams += ",innerWidth="+nWidth;
   sParams += ",height="+nHeight;
   sParams += ",innerHeight="+nHeight;
   sParams += ",dependent=yes";

   // Try to center the window (if we can)

   if (window.screen) {

      var nCenterWidth = (screen.availWidth)/2 - nWidth/2;
      var nCenterHeight = (screen.availHeight)/2 - nHeight/2;

      sParams += ",left="+nCenterWidth;
      sParams += ",screenX="+nCenterWidth;
      sParams += ",top="+nCenterHeight;
      sParams += ",screenY="+nCenterHeight;
 
   }
   hWindow = window.open(sURL, sWindow, sParams);
}