title: onreadystatechange function not being called
body: <p>For some reason, onreadystatechange call back function is not being called in asynchronous mode. I tested the post in synchronous mode and confirmed that post itself is working fine (commented out testing code I used to check post in synchronous mode). The problem occurs both in safari and firefox latest version. Can someone please tell me what I am doing wrong here? Thank you.</p>
  
  <pre><code>    &lt;html&gt;
      &lt;head&gt;
      &lt;script&gt;
      function recordScore(str)
      {
  
      if (str.length==0)
      { 
  
          return;
      }
  
      xmlHttp=GetXmlHttpObject();
      if (xmlHttp==null)
      {
          alert ("Your browser does not support AJAX!");
          return;
      } 
  
      var url="http://hellworld3.appspot.com/findcountry";
      var params = "screenname="+document.getElementById("screenname1").value+"&amp;score="+document.getElementById("score1").value;
      alert("params: "+params);
      xmlHttp.open("POST",url,true);
  
      xmlHttp.onreadystatechange = function() 
      {
          alert("entered call back function. readstate value is: "+xmlHttpreadyState+". Response Text is: "+xmlHttp.responseText);
  
      if (xmlHttp.readyState==4)
      { 
          document.getElementById("message").innerHTML=xmlHttp.responseText;
      }
      }
      xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded")
      xmlHttp.send(params);
  
      //Testing code for synchronous mode
      //alert("Http get status is: "+xmlHttp.status);
      //alert("Http ready state value is: "+xmlHttp.readyState);
      //alert("Http get response text is: "+xmlHttp.responseText);
      //document.getElementById("message").innerHTML=xmlHttp.responseText;
      }
  
  
      function GetXmlHttpObject()
      {
          var xmlHttp=null;
          try
          {
              // Firefox, Opera 8.0+, Safari
              xmlHttp=new XMLHttpRequest();
          }
          catch (e)
          {
              // Internet Explorer
              try
              {
                  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
              }
              catch (e)
              {
                  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
              }
          }
          return xmlHttp;
      }
  
      &lt;/script&gt;
  
  
      &lt;/head&gt;
  
  
      &lt;body&gt;
  
      &lt;form name="testform"&gt;
          Screename: 
          &lt;input type="text" id="screenname1" name="screenname"&gt;
          &lt;br/&gt;
          Score:
          &lt;input type="text" id="score1" name="score" onchange="recordScore(this.value)"&gt; 
          &lt;br/&gt;
          &lt;p id="message"&gt;test&lt;/p&gt;
  
          &lt;input type="submit" value="Submit"&gt;
      &lt;/form&gt;
  
      &lt;/body&gt;
  
  
      &lt;/html&gt;
  </code></pre>