facebook like box doesn't get display in IE8 but it is getting displayed in mozilla firefox ...

Question

hello,

I am working in php ... i want to display facebook like-box using javascript sdk ... my code is as follows :

in layout.php-

<script >
     window.fbAsyncInit = function() {
       FB.init({appId: appId , status: true, cookie: true,
                xfbml: true});
     };
     (function() {
       var e = document.createElement('script'); e.async = true;
       e.src = document.location.protocol +
         '//connect.facebook.net/en_US/all.js';
       document.getElementById('fb-root').appendChild(e);
     }());
  </script>

in php file :

<fb:like-box profile_id=ID  width="315" height="275" connections="10" stream="false" header="false" ></fb:like-box > 

with this code i can see like box in mozilla but not in IE ... also i am getting warning as "Undefined Tag" for fb:like-box ...

Please help me on this ... Thanks in advance ...