.each() > $(this).find().eq().html() is null
<p>Why don't work?</p>

<pre><code>var str;

$('table tr').each(function() {
    str = $(this).find('td').eq(6).html().trim().substring(10, 20);
    $(this).find('td').eq(6).text(str);
});
</code></pre>

<p>Need write in all 6th  trim+substring+another_string_action with same value.</p>

<p>Firebug write error: <strong>$(this).find("td").eq(6).html() is null</strong></p>
