getSilverlightVersion = function() {
    var SLVersion;
    try {
        try {
            var control = new ActiveXObject('AgControl.AgControl');
            if (control.IsVersionSupported("4.0"))
                SLVersion = 4;
            else if (control.IsVersionSupported("3.0"))
                SLVersion = 3;
            else if (control.IsVersionSupported("2.0"))
                SLVersion = 2;
            else
                SLVersion = 1;
            control = null;
        }
        catch (e) {
            var plugin = navigator.plugins["Silverlight Plug-In"];
            if (plugin) {
                if (plugin.description === "1.0.30226.2")
                    SLVersion = 2;
                else
                    SLVersion = parseInt(plugin.description[0]);
            }
            else
                SLVersion = 0;
        }
    }
    catch (e) {
        SLVersion = 0;
    }

    return SLVersion;
}