asp.net ajax contentchanged event of editor not firing.

sir,

I have try like below

<cc1:Editor ID="Editor1" runat="server"
        oncontentchanged="Editor1_ContentChanged" />
    <asp:Literal ID="Literal1" runat="server"></asp:Literal>

at codebehind

protected void Editor1_ContentChanged(object sender, EventArgs e)
    {
        Literal1.Text = Editor1.Content;

    }