Remove image link frame using CSS

Add below script into css file.

a img{ text-decoration : none;
border-bottom-style: none;
border-bottom-width: 0px;
border-top-style: none;
border-top-width: 0px;
border-left-style: none;
border-left-width: 0px;
border-right-style: none;
border-right-width: 0px; }