title: .net treeview ajax onclick
body: <p>This is my treeview:</p>
  
  <pre><code>&lt;asp:ScriptManager ID="ScriptManager1" runat="server"&gt;&lt;/asp:ScriptManager&gt;
  &lt;div style="width:100%;height:30px;float:left;line-height:30px;"&gt;
      &lt;asp:Label Text="Testo" runat="server" ID="tree_node" /&gt;
  &lt;/div&gt;
  
  &lt;div style="width:100%;height:400px;"&gt;
      &lt;div style="width:300px;float:left;"&gt;
          &lt;asp:TreeView ID="TreeView1" runat="server" OnSelectedNodeChanged="TreeView1_SelectedNodeChanged"&gt;&lt;/asp:TreeView&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  
  &lt;Asp:UpdatePanel runat="server" id="UP2"&gt;
      &lt;ContentTemplate&gt;
          &lt;asp:Image runat="server" ID="image" Width="200" Height="200" /&gt;
      &lt;/ContentTemplate&gt;
      &lt;Triggers&gt;
          &lt;asp:AsyncPostBackTrigger ControlID="TreeView1" EventName="selectedNodeChanged" /&gt;
      &lt;/Triggers&gt;
  
  &lt;/Asp:UpdatePanel&gt;
  </code></pre>
  
  <p>and this is the onselectmethod:</p>
  
  <pre><code>protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
  {
      tree_node.Text = TreeView1.SelectedNode.Value;
      image.ImageUrl = TreeView1.SelectedNode.Value;
  
  }
  </code></pre>
  
  <p>without updatepanel work but with the postback, what I need is to refresh image and label without the postback, so without the refresh of the page, where is the error?</p>