var xmlhttp = createRequestObject();

  function createRequestObject()
  {
    var ro;
    var browser = navigator.appName;

      if (browser == "Microsoft Internet Explorer")
      {
        ro = new ActiveXObject("Microsoft.XMLHTTP");
      }
      else
      {
        ro = new XMLHttpRequest();
      }

    return ro;
  }

  function updateBannerClicksInDb(url, query)
  { 
	  xmlhttp.onreadystatechange = confirmUpdate;
	  xmlhttp.open("POST", url, true);
	  xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
	  xmlhttp.send(query);
	}
 	
	function confirmUpdate()
	{
    if (xmlhttp.readyState == 4)
	  {
			if ( xmlhttp.status == 200)
			{
        if (xmlhttp.responseText == '1')
        {
         // document.write("everything went ok");
        }
        else if (xmlhttp.responseText == '0')
        {
          // document.write("everything didn't went ok");
        }
			}
    }
	}
	
	
 /****************************************************
 * Function: BannerClick
 * Desricption: Ajax function. Insert banner clicks into the database
 * Returnvalues: 1 - update in db was succesfull
 *               0 - update in db went wrong
 *               The return value isn't used... yet.
 *               It has been implemented for future updates
 ****************************************************/

 function BannerClick(banner_id)
 {
   var url = 'wp-content/plugins/banner/banner_clicks.php';
   var query = 'banner_id='+banner_id;
   
   updateBannerClicksInDb(url, query);
 }