Silverlight fullscreen using JavaScript Win 7
===

I am using a silverlight 2 based video player in my website. I am not able to run the silverlight video player in fullscreen through JavaScript code. The code I am using is 

    function media_expand()
    {
    document.getElementById("MainChannel").content.fullScreen= 'true';
    }

and the button in HTML calls the function

      <INPUT type="button"   onClick="media_expand()" >

it worked perfectly fine in Ubuntu 12.04 32bit OS, in FireFox but it is not working in any of Windows 7 browsers.

Please help.