// Silverlight detection in IE, Firefox and Safari.

    function isSilverlightInstalled()
    {
        var isSilverlightInstalled = false;
        try
        {
            //check on IE
            try
            {
                var slControl = new ActiveXObject('AgControl.AgControl');
                isSilverlightInstalled = true;
            }
            catch (e)
            {
                //either not installed or not IE. Check Firefox
                if ( navigator.plugins["Silverlight Plug-In"] )
                {
                    isSilverlightInstalled = true;
                }
            }
        }
        catch (e)
        {
            //we don't want to leak exceptions. However, you may want
            //to add exception tracking code here.
        }
        return isSilverlightInstalled;
    }