What is the problem on this jquery form that checks for number of chars in a textarea?
<p>this is a code that enables the submit button if there are more than 100 chars in the textarea. However I can't get it work. Maybe the jquery version is wrong? I don't know.</p>

<pre><code>&lt;script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"&gt;&lt;/script&gt;
&lt;form&gt;
  &lt;textarea id="textareaId"&gt;&lt;/textarea&gt;
  &lt;input type="submit" id="submitId" disabled="disabled" /&gt;
&lt;/form&gt;
&lt;script type="text/javascript"&gt;
  setInterval(function () {
    if(("#textareaId").val().length &gt; 100) {
      $("#submitId").removeAttr("disabled");
    } else {
      $("#submitId").attr("disabled", "disabled");
    }
  }, 500); //Runs every 0.5s
&lt;/script&gt;
</code></pre>
