Post value to new window from Gridview Selected column
<p>I tried to post the selected ID number from source page into a new target page(pop up window) and display more details on that page.</p>

<p>I have googled the varies solutions but seem like they are a bit out of date.
Here are my questions:</p>

<p>What's the best way to post it (session? cookie?) or <code>Page.PreviousPage.FindControl</code>? or add a control into <code>&lt;ItemTemplate&gt;</code>? or Javascript?</p>

<p>I don't want to use a query string since I don't want the user to manually modify it.</p>

<p>What should I write on the target page to grab that value?</p>

<pre><code>protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
    string testID= GridView1.SelectedRow.Cells[3].Text;
    // eg. Session["ID"] = testID;

    //eg. open new pop up window ("target.aspx");
}
</code></pre>

<p>Many thx</p>
