Passing DataKeys between pages
<p>Using a GridView on the default page and want to show details of the row selected on another page.  The code for capturing and sending the datakey is -</p>

<pre><code>protected void SelectedIndexChanged(object sender, EventArgs e)
{
            int index = GridView1.SelectedIndex;
            Response.Redirect("InvoicePage.aspx? EntityID= " + GridView1.DataKeys[index].Value.ToString()); 
}
</code></pre>

<p>And the code for retrieving the value is -</p>

<pre><code>protected void Page_Load(object sender, EventArgs e)
{
    string id = Request.QueryString["EntityID"];
}
</code></pre>

<p>My problem is that the id variable is a null on the receiving page.  What am I missing?</p>
