Get rid of the border of a linked image

CSS:

.entry-content a:link,.entry-content a:visited {
    color:Black;
    text-decoration:none;
	border-bottom: 1px dotted black;
}
.entry-content a:hover {
	color:Black;
    text-decoration:none;
	border-bottom: 1px solid black;
}
.more-link {
}
.more-link a:link img.noborder{
	border:none;
}
.entry-content img.noborder{
    border:none;
}
.entry-content a img.noborder{
    text-decoration:none;
    border-bottom:none;
}

Actual HTML output:
<div class="entry-content">abc<a href="abc" class="more-link"><img class="noborder" src="abc" /></a></div>

As you can tell from the CSS file, I have this ‘border-bottom’ for all my links, but i want to get rid of this ‘border-bottom’ for a specific image within the div ‘entry-content’. Anyone can tell me how do I do it?