function doPopup(url,width,height)
{
   var posX, posY; // position of popup

   if (!width)
   {
      width = 610;
   }

   if (!height)
   {
      height = 340;
   }

   var offsetX = 100, offsetY = 100;  // x and y offset relative to the parent window

   if (typeof window.screenLeft != "undefined")  // IE
   {
      posX = window.screenLeft + offsetX;
      posY = window.screenTop + offsetY;
   }
   else if (typeof window.screenX != "undefined")  // NS/Moz
   {
      posX = window.screenX + offsetX;
      posY = window.screenY + offsetY;
   }

   var win = window.open(url,'win','width=' + width + ',height=' + height + ',top=' + posY + ',left=' + posX + ',toolbar=no,location=no,directories=no,scrollbars=no');

   win.focus();
}