Get element by tag and class
<p>I have a script</p>

<pre><code>var firstImg = row.getElementsByTagName('img')[0];
</code></pre>

<p>and later </p>

<pre><code>if (x){ firstImg.src='/images/checked.png'; }
</code></pre>

<p>I'd like to define that the img should be of <code>class='something'</code></p>

<p>(Get first img with class='something')
10x in advance!</p>
