title: Cannot enable XHTML submit input/button which is disabled by default
body: <p>I have this simple button in XHTML:</p>
  
  <pre><code>&lt;input type="submit" name="submit" value="Test" disabled="disabled" onmouseover="this.disabled=''" /&gt;
  </code></pre>
  
  <p>The problem is, no matter what I try, when I hover over the button, it won't re-enable from the disabled attribute it has. In XHTML, you are required to use <code>disabled="disabled"</code> which seems to completely break the option to enable/disable it with JavaScript. I've tried running <code>this.disabled=''</code>, <code>this.disabled=false</code>, and even <code>this.removeAttribute('disabled')</code> but nothing seems to be capable of re-enabling the button. Weird thing is, if I remove the <code>='disabled'</code> part of the attribute (making it invalid XHTML), the script enables the button just fine. Is this not possible without using invalid XHTML?</p>
  
  <p><strong>Note:</strong> I'd really prefer to only use JavaScript for this specific example, not jQuery.</p>
  
  <p>I thought this would be something simple that would take like 5 seconds but apparently not.</p>