var imgVT = document.createElement("img");
imgVT.src = "VTInstalled.aspx?isInstalled=" + ((isVirtoolsInstalled())?"1":"0") + "&r=" + randomString() + "&visitId=" + visitId;
   
function isVirtoolsInstalled()
{
   if (navigator.plugins && navigator.plugins.length > 0)
   {
      return getPluginIndex() > -1;
   }
   if (is_ie5up)
   {
      document.write('<SCRIPT LANGUAGE=VBScript\> \n');
      document.write('on error resume next \n')
      document.write('set tSWControl = CreateObject("VirtoolsWebPlayerDll.VirtoolsWebPlayer.1") \n');
      document.write('isLoaded = IsObject(tSWControl) \n');
      document.write('</SCRIPT\> \n');
      return isLoaded;
   }      
   return false;
}
function getPluginIndex()
{
   for(var i = 0; i < navigator.plugins.length; ++i)
   {
      var myplug = navigator.plugins[i];       
      var index = myplug.filename.lastIndexOf('\\');
      if (index != -1)
      {
         sub = myplug.filename.substring(index+1,myplug.filename.length);
         if (sub.toLowerCase() == "npvirtools.dll" || sub.toLowerCase() == "npvirtools" )
         {
            return i;
         }
      } 
      else if (myplug.filename.toLowerCase() == "npvirtools.dll" || myplug.filename.toLowerCase() == "npvirtools")
      {
         return i;
      }
   }
   return -1;
}
//found at: http://www.mediacollege.com/internet/javascript/number/random.html
function randomString() {
	var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
	var string_length = 8;
	var randomstring = '';
	for (var i=0; i<string_length; i++)
	{
		var rnum = Math.floor(Math.random() * chars.length);
		randomstring += chars.substring(rnum,rnum+1);
	}
	return randomstring;
}