Given the following html, how can I get the contents of the div, jims_class, to show and hide depending upon the checked status of the mybox1 checkbox?

<script>
  if ($('#mybox1').attr('checked')) {
    $('.jims_class').show());
  }
  else {
    $('.jims_class').hide());
  }
</script>

<form>
  <input type="checkbox" name="mybox1" id="mybox1">
  <input type="checkbox" name="mybox2" id="mybox2">
</form>

<div class="jims_class">
Conditionally show this text depending on the checked status of mybox1
+...
</div>

[download]