title: Updatepanel inside usercontrol ascx file not updating gridview
body: <p>I'm trying to be slick and I'm putting this user control in a div that covers the whole page.
  However when I click on the search button I get a full postback.
  Any ideas on how to get it to not postback and just update the gridview?</p>
  
  <p>And just to be clear. The following control is in a ascx file. Which is called in a aspx page.</p>
  
  <pre><code>&lt;%@ Control Language="C#" AutoEventWireup="true" CodeFile="PropertyViewAddEntity.ascx.cs"
  Inherits="UserControls_PropertyViewAddEntity" %&gt;
  
  &lt;p&gt;Search for State City County zip&lt;/p&gt;
          &lt;asp:Panel ID="Panel1" runat="server" DefaultButton="Button2ae"&gt;
              &lt;p&gt;
                  &lt;asp:TextBox ID="TextBox1ae" runat="server" Width="500px"&gt;&lt;/asp:TextBox&gt;
                  &lt;asp:Button ID="Button2ae" runat="server" Text="Search"  CausesValidation="false" /&gt;
              &lt;/p&gt;
          &lt;/asp:Panel&gt;
          &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"&gt;
              &lt;ContentTemplate&gt;
                  &lt;asp:GridView ID="GridView2ae" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource3ae"
                      OnSelectedIndexChanged="GridView2ae_SelectedIndexChanged"&gt;
                      &lt;Columns&gt;
                          &lt;asp:CommandField ShowSelectButton="True" /&gt;
                          &lt;asp:BoundField DataField="zipcodeid" HeaderText="zipcodeid" SortExpression="zipcodeid" /&gt;
                          &lt;asp:BoundField DataField="zip_code" HeaderText="zip_code" SortExpression="zip_code" /&gt;
                          &lt;asp:BoundField DataField="state" HeaderText="state" SortExpression="state" /&gt;
                          &lt;asp:BoundField DataField="city_alias_name" HeaderText="city_alias_name" SortExpression="city_alias_name" /&gt;
                          &lt;asp:BoundField DataField="county_name" HeaderText="county_name" SortExpression="county_name" /&gt;
                      &lt;/Columns&gt;
                  &lt;/asp:GridView&gt;
  
              &lt;/ContentTemplate&gt;
              &lt;Triggers&gt;
                  &lt;asp:AsyncPostBackTrigger ControlID="Button2ae" EventName="Click" /&gt;
              &lt;/Triggers&gt;
          &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>btw the control is in a placeholder</p>
  
  <pre><code>&lt;asp:PlaceHolder ID="ControlContainer" runat="server"/&gt;
  </code></pre>
  
  <p>and called from the code behind.</p>
  
  <pre><code>Control mycontrol = LoadControl("~/UserControls/PropertyViewAddEntity.ascx");
  
      ControlContainer.Controls.Add(mycontrol);
  </code></pre>