I am using jQuery Tabs to display images.
The HTML, also viewable on jfiddle follows:
<div id="dgTabs" style="width: 500px;">
<ul>
<li><a id="a1" href="tab-1">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /></a></li>
<li><a id="a2" href="tab-2">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /> </a></li>
<li><a id="a3" href="tab-1">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /></a></li>
<li><a id="a4" href="tab-2">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /> </a></li>
<li><a id="a5" href="tab-1">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /></a></li>
<li><a id="a6" href="tab-2">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /> </a></li>
<li><a id="a7" href="tab-1">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /></a></li>
<li><a id="a8" href="tab-2">
<img src="http://images.smh.com.au/2012/10/30/3754903/umbrella_tn-90x60.jpg" /> </a></li>
</ul>
</div>
How can I change the CSS so the image fills the whole tab? Which element in which CSS file do I need to update? Basically, I want no padding.

this padding is present in
jquery-ui.cssfile, you need to override below paddingUpdated
To set width you have to do like following