Popextender closes the panel after commit
<p>I'm creating a panel with a multi select CheckBoxList, attached to a TextBox through a PopControl extender.</p>

<p>I'm using the <code>.commit()</code> method of the <code>PopControl</code> extender to display the selected item.</p>

<p>When I select an item from the CheckBoxist the panel closes, and I want to select the item without closing the panel.</p>

<p>What am I doing wrong?</p>

<p><strong>Markup</strong></p>

<pre><code>&lt;asp:TextBox ID="txtCountry" runat="server" Skinid="longTextbox" AutoPostBack = "false" OnClientItemSelected="passtohidden()" /&gt;
&lt;asp:Panel ID="pnlLocation" runat="server"&gt;
    &lt;asp:UpdatePanel runat="server" ID="upLocation"&gt;
        &lt;ContentTemplate&gt;
            &lt;asp:CheckBoxList ID="chkLocation" SkinID ="chkColor" runat="server" AutoPostBack = "true" onselectedindexchanged="chkLocation_SelectedIndexChanged" /&gt;
        &lt;/ContentTemplate&gt;
        &lt;Triggers&gt;
            &lt;asp:AsyncPostBackTrigger ControlID="txtCountry" EventName="TextChanged" /&gt;
        &lt;/Triggers&gt;
    &lt;/asp:UpdatePanel&gt;
&lt;/asp:Panel&gt;
&lt;asp:PopupControlExtender ID="Panel1_PopupControlExtender" runat="server" Enabled="True" Position="Bottom" PopupControlID = "pnlLocation" TargetControlID="txtCountry" /&gt;
</code></pre>

<p><strong>Code behind</strong></p>

<pre><code>protected void chkLocation_SelectedIndexChanged(object sender, EventArgs e)
{
    string strSelected = "";

    foreach (ListItem l in chkLocation.Items)
    {
        if (l.Selected)
        {
            strSelected += l.Text + " ,";
        }
    }

    //txtCountry.Text = strSelected;

    Panel1_PopupControlExtender.Commit(strSelected);
}
</code></pre>
