/** XHConn - Simple XMLHTTP Interface - bfults@gmail.com - 2005-04-08        **
            ** Code licensed under Creative Commons Attribution-ShareAlike License      **
            ** @ modified by Phuc Phan 
            ** @ email ptp285@gmail.com
            ** http://creativecommons.org/licenses/by-sa/2.0/                           **/
    function XHConn()
    {
      var xmlhttp, bComplete = false;
      try { xmlhttp = new ActiveXObject("Msxml2.XMLHTTP"); }
      catch (e) { try { xmlhttp = new ActiveXObject("Microsoft.XMLHTTP"); }
      catch (e) { try { xmlhttp = new XMLHttpRequest(); }
      catch (e) { xmlhttp = false; }}}
      if (!xmlhttp) return null;
      this.connect = function(divID, sURL, sMethod, sVars)
      {
        if (!xmlhttp) return false;
        bComplete = false;
        sMethod = sMethod.toUpperCase();
        try {
          if (sMethod == "GET")
          {
            xmlhttp.open(sMethod, sURL, true);
            sVars = "";
          }
          else
          {
            xmlhttp.open(sMethod, sURL, true);
            xmlhttp.setRequestHeader("Method", "POST "+sURL+" HTTP/1.1");
            xmlhttp.setRequestHeader("Content-Type",
              "application/x-www-form-urlencoded");
          }
          xmlhttp.onreadystatechange = function(){
            if (xmlhttp.readyState == 4 && !bComplete)
            {
              bComplete = true;
              //fnDone(divID, xmlhttp);
              document.getElementById(divID).innerHTML = xmlhttp.responseText;
            }else{
              //document.getElementById(divID).innerHTML = '<center><img src="images/loading.gif"> <font size=4>Loading ...</font></center>';
            }
          };
          xmlhttp.send(sVars);
        }
        catch(z) { return false; }
        return true;
      };
      return this;
    }
    function showTagAjax(divID, urlString, queryString, showLoading, sMethod) {
        if(''+showLoading == 'undefined') {
          showLoading = true;
        }
        if(showLoading) {
          document.getElementById(divID).innerHTML = '<center><img src="/images/loading.gif"> <font size=4>Loading ...</font></center>'
        }
        if(''+sMethod == 'undefined') {
          sMethod = "GET";
        }

        //initialize XHConn (if XHConn isn't created successfully, 
        //the client doesnt' support Ajax)
        var ajaxConn = new XHConn();
        
        var url = urlString;
        if (sMethod == "GET") {
          if ( url.indexOf("?") == -1)
            url = url+"?sid="+Math.random();
          else
          url = url+"&sid="+Math.random();
          url = url+"&"+queryString;
        }

        ajaxConn.connect(divID, url, sMethod);
    }
  function emptyTag(tag) {
    document.getElementById(tag).innerHTML = '';
  }
  function changeTag(tag, content) {
    document.getElementById(tag).innerHTML = content;
  }