问jQuery表格扩展器在Chrome中有效，但在火狐中不起作用

EN

$(document).ready(function() {
    // set code boxes up for expanding
    var site_width = $('.entry-content').width();
    $('table.highlighttable').each(function() {
        // store each code block's width in its tabindex for later retrieval
        $(this).attr('tabindex', $(this).width());
    });
    // initially restrict all code blocks to site width (could be CSS really)
    $('table.highlighttable').css('width', site_width);
    // add button to each code block to expand / collapse
    $('.code pre').append('<a href="#" class="code-expand">&raquo;</a>');
    jQuery(".code-expand").click(function() {
        var natural_width = $(this).closest('table.highlighttable').attr('tabindex');
        var site_width = $('.entry-content').width();
        if($(this).closest('table.highlighttable').width() > site_width) {
            // if code is expanded, collapse code
            $(this).closest('table.highlighttable').css('width', site_width);
            $(this).html('&raquo');
        } else {
            // if code is collapsed, expand code
            $(this).closest('table.highlighttable').css('width', natural_width);
            $(this).html('&laquo');
        }
        return false;
    });
});

<div class="entry-content">
  <table class="highlighttable">
    <tr>
      <td class="code">
        <div class="highlight"><pre>
      stuffstuffstuffstuffstuffstuffstuffstuffstuffstuffstuffstuffstuff
          </pre>
        </div>
      </td>
    </tr>
  </table>
</div>

.entry-content {
  width:300px;
  border:1px solid #000;
}
.highlighttable {
  table-layout:fixed;
  border:1px solid #F00;
}