title: ContentPlaceHolder in UpdatePanel
body: <p>I have very simple a ajax enabled asp .net website with masterpage. I have a menu in master page and the other pages appear in MainContent placeholder. I have the following code.But when I click to the menu items i can see that sometimes page postbacks. </p>
  
  <pre><code>&lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Always"&gt; 
     &lt;ContentTemplate&gt;
         &lt;asp:ContentPlaceHolder ID="MainContent" runat="server" /&gt;
     &lt;/ContentTemplate&gt;
  </code></pre>
  
  <p></p>
  
  <p>How can i prevent the postback and the partial load of the page ? I have searched the stackoverflow but all the solutions are same as what i do as far as i see. Is there something that i need to do ?</p>
  
  <p>Thanks.</p>
  
  <p>Edit:
  the complete page with the menu items is as follows:</p>
  
  <pre><code>&lt;asp:ScriptManager ID="ScriptManager1" runat="server"&gt;
  &lt;/asp:ScriptManager&gt;
  &lt;div class="page"&gt;
      &lt;div class="header"&gt;
          &lt;div class="title"&gt;
              &lt;h1&gt;
                  App&lt;/h1&gt;
          &lt;/div&gt;
          &lt;div class="loginDisplay"&gt;
          &lt;/div&gt;
          &lt;div class="clear hideSkiplink"&gt;
              &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;
              &lt;asp:Menu ID="NavigationMenu" runat="server" EnableViewState="false" IncludeStyleBlock="false"
                  Orientation="Horizontal" Font-Size="Large" Height="48px" Width="100%" BorderStyle="Dashed"&gt;
                  &lt;Items&gt;
                      &lt;asp:MenuItem NavigateUrl="~/Default.aspx" Text="Home Page" /&gt;
                      &lt;asp:MenuItem NavigateUrl="~/DefinePropertyType.aspx" Text="Define PropertyType" /&gt;
                      &lt;asp:MenuItem NavigateUrl="~/CreateProperty.aspx" Text="Create Property" /&gt;
                      &lt;asp:MenuItem NavigateUrl="~/RiskManagemet.aspx" Text="Risk Managemet" /&gt;
                      &lt;asp:MenuItem NavigateUrl="~/InsurancePolicy.aspx" Text="InsurancePolicy" /&gt;
                      &lt;asp:MenuItem NavigateUrl="~/Damage.aspx" Text="Damage" /&gt;
                  &lt;/Items&gt;
                  &lt;StaticMenuItemStyle ItemSpacing="20px" /&gt;
              &lt;/asp:Menu&gt;
          &lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="main"&gt;
          &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Always"&gt; 
              &lt;ContentTemplate&gt;
                  &lt;asp:ContentPlaceHolder ID="MainContent" runat="server" /&gt;
              &lt;/ContentTemplate&gt;
          &lt;/asp:UpdatePanel&gt;
      &lt;/div&gt;
      &lt;div class="clear"&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="footer"&gt;
  </code></pre>