// Variables
	  var xmlHttp;
      var responseText = "";
      var responseXml;
      var url = "";
      var http = "";
      var method = "GET";
      var isAsynchronous = true;
      var requestData = "";
      var elementID = "";
      var thisObj = this;
      var pagePath = "";
      var isXml = false;
      var isMozilla = false;

      //Gets the text reponse of the server.
      this.getResponseXml = function () 
      { 
      return responseXml;
      }

      // Events
      this.onRequestComplete = function () 
      {
      };

      function createXMLHttpRequest ()
      {
          if (window.ActiveXObject)
          {
              xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
              if (xmlHttp ==  null)
              {
                 xmlHttp = new ActiveXObject ("Msxml2.XMLHTTP");
              }
          }
           else if (window.XMLHttpRequest)
           {
            xmlHttp = new XMLHttpRequest(); isMozilla = true;
           }
           else
           {
             alert("The XMLHttpRequest nor ActiveXObject object could not be created.");
           }
      }

      // Sends a get request.
      function sendGetRequest(urlquery, handleServerResponseFunction)
      {
      //prevent caching
      urlquery += "&timestamp=" + new Date().getTime();
      // create xml http request
      createXMLHttpRequest();
      // handle server response
      xmlHttp.onreadystatechange = handleServerResponseFunction; 
      // open
      //
      //
      xmlHttp.open(method, urlquery, isAsynchronous);
      if (isXml)
      {
      if (isMozilla) xmlHttp.overrideMimeType('text/xml');
      xmlHttp.setRequestHeader("Content-Type", "text/xml");
      }
      xmlHttp.send(null); // send
      }
      
      // Handles server's response: newsletter
      function handleServerResponseNewsletter()
      {
          if(xmlHttp.readyState == 4)
          {
              if(xmlHttp.status == 200)
              {
                responseText = xmlHttp.responseText;
                responseXml = xmlHttp.responseXML;
              }
              // set newsletter content
              document.getElementById('newsletterdiv').innerHTML=responseText;
          }
      }
      

      // Handles server's response: survey
      function handleServerResponseSurvey()
      {
          if(xmlHttp.readyState == 4)
          {
              if(xmlHttp.status == 200)
              {
                responseText = xmlHttp.responseText;
                responseXml = xmlHttp.responseXML;
              }
              // set survey content
              document.getElementById('surveydiv').innerHTML=responseText;
          }
      }
      
      // Handles server's response: article pages
      function handleServerResponseArticlePages()
      {
                  
          if(xmlHttp.readyState == 4)
          {
              if(xmlHttp.status == 200)
              {
                responseText = xmlHttp.responseText;
                responseXml = xmlHttp.responseXML;
              }
              // set article pages content
              document.getElementById('articlepagesdiv').innerHTML = responseText;
          }
      }
       
      // Handles server's response: article vote
      function handleServerResponseArticleVote()
      {
                  
          if(xmlHttp.readyState == 4)
          {
              if(xmlHttp.status == 200)
              {
                responseText = xmlHttp.responseText;
                responseXml = xmlHttp.responseXML;
              }
              // set article vote content
              document.getElementById('articlevotediv').innerHTML = responseText;
          }
      }