XmlHttpCrossDomain Request in javascript

<script type="text/javascript">
        var xhr = new XMLHttpRequest();

        xhr.open("GET", "http://www.bing.com/images/search?q=sunset&go=&qs=n&form=QBLH&filt=all&pq=sunset&sc=8-6&sp=-1&sk=", true);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4) {
                if (xhr.status == 200 || xhr.status == 0) {
                    alert(xhr.statusText);
                    alert(xhr.responseText);
                } else {
                    alert("ERROR");
                }
            }
        };
        xhr.send(null);  
    </script>

Hi am using this code for getting the response text from the server.
xht.status is coming 200 in IE and xhr.status is coming 0 in mozila.
Responsetext is coming in IE but in mozila responsetext is coming empty.

If i once published this code means also am not getting the responsetext.

Please any one help me to how to get the responsetext in mozila and after published in server

sakthi