title: ASP.Net AJAX UpdatePanel not working with Repeater and RadioButtons
body: <p>I have a repeater which includes a radio button in each item, and the whole thing sites inside an update panel.  When I select a radio button the whole page reloads.  Why is it not just updating the update panel.  I've reduced this to a pretty simple example to avoid clutter.  Code here...</p>
  
  <p>ASPX...</p>
  
  
  
  <p>
  
  </p>
  
  <pre><code>&lt;asp:ScriptManager ID="SM1" runat="server" /&gt;
  &lt;asp:UpdatePanel ID="up1" runat="server" UpdateMode="Conditional"&gt;
      &lt;ContentTemplate&gt;
          &lt;asp:Repeater runat="server" ID="history"&gt;
              &lt;ItemTemplate&gt;
                  &lt;asp:RadioButton runat="server" ID="radioButton" AutoPostBack="true" GroupName="HistoryGroup" OnCheckedChanged="RadioButton_CheckChanged" /&gt;&lt;br /&gt;
              &lt;/ItemTemplate&gt;
          &lt;/asp:Repeater&gt;
  
          &lt;p&gt;&lt;asp:Literal runat="server" ID="output" /&gt;&lt;/p&gt;
      &lt;/ContentTemplate&gt;
  &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p></p>
  
  <p>Code...</p>
  
  <pre><code>public partial class _Default : System.Web.UI.Page
  {
      protected void Page_Load(object sender, EventArgs e)
      {
          if (!Page.IsPostBack)
          {
              List&lt;int&gt; list = new List&lt;int&gt;();
              for (int i = 0; i &lt; 20; i++)
                  list.Add(i);
              history.DataSource = list.ToArray();
              history.DataBind();
          }
      }
  
      protected void RadioButton_CheckChanged(Object sender, EventArgs e)
      {
          output.Text = DateTime.Now.ToString();
      }
  }
  </code></pre>