Silverlight RegisterScriptableObject scriptkey is always null

Had to post here this doesn't make any sense to me.

I am trying to call Silverlight functions from my java开发者_运维知识库script and the scriptkey I am using always comes up null.

I have this img in my markup that I want to initiate the Silverlight code.

<img alt="stop" src="stop.jpg" onclick="CallSilverlight();" />

Clicking that runs this JavaScript function.

function CallSilverlight() {
            var control = document.getElementById("silverlightControlHost");
            control.Content.Page.DoStuff();
        }

DoStuff() is a function in my silverlight object I am trying to register it as scriptable by using this code in my silverlight class.

public Main()
{
     InitializeComponent();
     HtmlPage.RegisterScriptableObject("Page", this);
}

[ScriptableMember]
public void DoStuff()
{
     MessageBox.Show("Hello from SL");
}

No idea what is wrong here, this is just like all the examples on the web but my Page in control.Content.Page.DoStuff(); throws this javascript error, am I missing something, this is driving me crazy.

Line: 67 Error: Unable to get value of the property 'Page': object is null or undefined