uncaught exception: [Exception... "Component returned failure code: 0xc1f30001 (NS_ERROR_NOT_INITIALIZED) [nsIXMLHttpRequest.send]" nsresult: "0xc1f30001 (NS_ERROR_NOT_INITIALIZED)" location: "JS frame ::

<script type="text/javascript">

 try {
 xmlHttp = new ActiveXObject('MSXML2.XMLHTTP');
 } catch(e)
 {
  
}
try {
 xmlHttp = new ActiveXObject('Microsoft.XMLHTTP');
} catch(e) {
  alert("Your Browser doesnt support AJAX");
}

try {
xmlHttp = new XMLHttpRequest();
} catch(e) {
 alert("AJAX n0t supported");
}



function Asx()
{
 xmlHttp.send("GET", "a.php", true);
 xmlHttp.open();
 var msg = document.getElementById('msg');

 xmlHttp.openReadyStateChange = responseAsx(); 
}

function responseAsx()
{
 msg.innerHTML = xmlHttp.responseText;

 if (xmlHttp.readyState == 4 )
 {
  msg.innerHTML = "Worked!";
 } else if (xmlHttp.readyState != 4 ) 
{
 document.write('Loading..');
 }
}