.share-link {
display: block;
width: 41px;
height: 32px;
text-decoration: none;
background: url("link-icon.png");
}

.share-link:hover {
background-position: -41px 0;
}


<a title="Share this Link" href="#"><img class="share-link"></a>

*:focus {outline: none;}

.nohighlight:focus  {  outline:none;  }

#dlbutn {
    display:block;
    width:0px;
    height:0px;
    outline:none;
    padding:43px 51px 43px 51px;
    margin:0 auto 5px auto;
    background-image:url(/images/download-button-102x86.png);
    background-repeat:no-repeat;
}

<img class="share-link"  src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"/>

a image {border: none} or a image {border: 0}