The name 'placeholderName' does not exist in the current context
<p>I have added placeholder to a page as below.</p>

<pre><code>&lt;tr &gt; 
 &lt;td &gt;
  &lt;asp:PlaceHolder ID="phMemberName" runat="server" &gt;
  &lt;/asp:PlaceHolder&gt;
 &lt;/td&gt;
 &lt;td&gt;
 &lt;asp:PlaceHolder ID="phMemberTextboxes" runat="server"&gt;
 &lt;/asp:PlaceHolder&gt; 
&lt;/td&gt;
 &lt;/tr&gt;
</code></pre>

<p>I am adding controls(checkboxes) to it dynamically to it.
It works fine but it throws an error if run in debug mode.
What is the reason ?</p>

<p>The error is </p>

<blockquote>
  <p>The name 'phMemberName' does not exist in the current context</p>
</blockquote>
