C# Master-Details (Separate Pages)

My question is setting up master detail pages using stored procedrues.  In the tutorials C# Master-Details (Seperate Pages) example they use the following code for the master page for the navigation.

          <asp:HyperLinkField HeaderText="View Details..." Text="View Details..." DataNavigateUrlFields="au_id"
            DataNavigateUrlFormatString="DetailsView_cs.aspx?ID={0}" />


The call to the Details Page DetailsView_cs.aspx uses the following code

 <asp:SqlDataSource ID="SqlDataSource1" Runat="server" SelectCommand="SELECT dbo.authors.au_id, dbo.titles.title_id, dbo.titles.title, dbo.titles.type, dbo.titles.price, dbo.titles.notes FROM dbo.authors INNER JOIN dbo.titleauthor ON dbo.authors.au_id = dbo.titleauthor.au_id INNER JOIN dbo.titles ON dbo.titleauthor.title_id = dbo.titles.title_id WHERE (dbo.authors.au_id = @au_id)"
        ConnectionString="<%$ ConnectionStrings:Pubs %>">
        <SelectParameters>
          <asp:QueryStringParameter Name="au_id" DefaultValue="213-46-8915" QueryStringField="ID" />
        </SelectParameters>
      </asp:SqlDataSource>


I can replicate the example calling the detail page but I am unable to make the detail page work when using a stored procedure as the asp:SQLDataSource. Using the above sql code as a stored procedure in the  <SelectParameters>  I am not able to return the data set using either asp:QueryStringParameter or asp:Parameter as I have built other forms using stored procedures and have tested the procedure and know that it works. Can someone point me in the right direction.

Thanks