Convert jquery function into javascript
<p>I have to use javascript for below mention work which is done in jquery and working perfect. Reason to use javascript is to know how it can be done with javascript.I google it but not find any clue to how get it done</p>

<p><a href="http://jsfiddle.net/2vP24/" rel="nofollow">http://jsfiddle.net/2vP24/</a></p>

<pre><code>$('.first').find('.sub1').next().css('background','#ff0000')
</code></pre>
