title: When will <td valign="top"> not work?
body: <p>Have you  ever concluded about this?</p>
  
  <p>Now I've met one, very strange, don't know why.</p>
  
  <p>My code:</p>
  
  <pre><code>&lt;td valign="top"&gt;
      &lt;input type="text" /&gt;
      &lt;iframe scrolling="no" height="21px" frameborder="0" width="62px" marginheight="0" marginwidth="0" src="Server/SecCode.php"&gt;
      &lt;/iframe&gt;
  &lt;/td&gt;
  </code></pre>
  
  <p>But it turns out to be that the "input" is valigned to the bottom,while "iframe" to the top.</p>