using Databinder.Eval in onclick of checkbox in datagrid

<asp:DataGrid ID="dg" runat="server">
    <Columns>
        <asp:TemplateColumn>
            <ItemTemplate>
                <asp:CheckBox ID="cb" runat="server" onclick='myCheckChanged("<%#DataBinder.Eval(Container, "DataItem.myid")%>")' />
            </ItemTemplate>
        </asp:TemplateColumn>
    </Columns>
</asp:DataGrid>

This runs but when I click the checkbox in the browser I get a js error. I tried all the combinations of single and double quotes and escaping but i either get a js error or a .net "The server tag is not well formed" error. how can I do this?