title: Prototype select all checkboxes code works in IE, but not Firefox
body: <p>I'm using prototype 1.6.0.1.  I'm trying to select all the checkboxes when clicking a button.  This code works in IE 6, but does NOT in Firefox 3.  What am I doing wrong?</p>
  
  <pre><code>&lt;input class="submit" type="button" value="check all" onclick="$(this.form).getInputs('checkbox').each(function (elem) {elem.checked = true;});" /&gt;
  </code></pre>