Removing link decoration from an image while still keeping a border

[simontheak]

I've come across a problem with the images I'm using as links.

I want to remove the ugly blue border that naturally comes from using an <a> tag with an image ... but I still want to include a dotted right border to separate the image from the following picture.

You can see what I mean by looking at the icons in the top right hand corner at http://www.theshortstack.co.uk

I've tried using the following CSS:

img.firsticon {
padding-right: 5px;
}

img.firsticon a{
text-decoration: none;
} 

It's obviously not working though.

Would somebody be able to point out where I'm going wrong please?

Thanks very much