How to get rid of border around and image used as a link in Firefox?

Links (<a>’s) by default have a dotted outline around them when they become “active” or “focused”. In Firefox 3, the color is determined by the color of the text

To remove it, simply use:

a {
    outline: none;
}

Or you can do what I do, and remove it from all elements (I use my own focus/active rules) and do

* {
    outline: none;
}

This will remove it from all elements.