HTMLDocument getElementById for a custom control returns null, why, and is there a different way to access it?
<p>I have the following in an aspx page inside a body tag:</p>

<pre><code>&lt;form id="Form1" method="post" runat="server"&gt;
 &lt;customControl:menu id="Menu1" runat="server"&gt;
 &lt;/customControl:menu&gt;
&lt;/form&gt;
</code></pre>

<p>And from a different aspx page I have this javascript function:</p>

<pre><code>&lt;script type="text/javascript"&gt;
 function testFunction(args, name) {
  alert(top.frames[0].document);      //gives me [object HTMLDocument]
  alert(top.frames[0].document.getElementById("Form1"));  //gives me [object HTMLFormElement]
  alert(top.frames[0].document.getElementById("Menu1"));      //gives me [null]
 }
&lt;/script&gt;
</code></pre>

<p>Why is the third alert giving me null? (The <code>menu</code> is a control with an <code>ascx</code> extension)</p>

<p>Thanks,
Voodoo</p>
