Ajax issue in WebSphere+firefox-- Please help!!

[xaja-newBie]

Hi,

i am trying to clear the user authentication cache with the below code for IE and FireFox browser.. it works well when deployed in my local environment(win7, IE8,FireFox19.0,tomcat 4.1.36) in tomcat server. but it is not working in Firefox after deploying in (Unix, WebSphere6.1,Firefox19.0). can somebody help me what could be wrong??

my first approach::
<code>
function clearCache(){
var ua= window.navigator.userAgent;
if(ua.indexOf("MSIE") > 0){
document.execCommand("ClearAuthenticationCache");
return true;
}else{
$.ajax({
url: '<%=request.getContextPath()%>/pages/PeleLogout.jsp',
username: ' ',
password: ' ',
statusCode: { 401: function() { //alert('Logged Out')
}
}
});
return true;
}
}
</code>

my second approach ::
<code>
function clearCache(){
alert(" in clearCache");
if(window.navigator.userAgent.indexOf("MSIE")>0){
alert(" is IE Browser");
document.execCommand("ClearAuthenticationCache");
}else{
alert(" is not an IE Browser");
var xmlhttp=createXMLObject();

xmlhttp.open("GET","URL",true,"logout","logout");
xmlhttp.send("");
xmlhttp.abort();
}
}

function createXMLObject(){
try
{
if(window.XMLHttpRequest){xmlhttp= new XMLHttpRequest();}
else if (window.ActiveXObject){xmlhttp= new ActiveXObject("Microsoft.XMLHTTP");}

}catch(e){

xmlttp=false

}
return xmlhttp;

}
</code>

both first approach and second approach works well in my local tomcat server, but after deploying into websphere6.1 server both the versions fail to work in firefox, any help in this regard is highly appreciated

Regards,
axaj-newBie