CSS代码：

<style type="text/css">

.gallerycontainer{
position: relative;
/*Add a height attribute and set to largest image's height to prevent overlaying*/
}

.thumbnail img{
border: 1px solid white;
margin: 0 5px 5px 0;
}

.thumbnail:hover{
background-color: transparent;
}

.thumbnail:hover img{
border: 1px solid blue;
}

.thumbnail span{ /*CSS for enlarged image*/
position: absolute;
background-color: lightyellow;
padding: 5px;
left: -1000px;
border: 1px dashed gray;
visibility: hidden;
color: black;
text-decoration: none;
}

.thumbnail span img{ /*CSS for enlarged image*/
border-width: 0;
padding: 2px;
}

.thumbnail:hover span{ /*CSS for enlarged image*/
visibility: visible;
top: 0;
left: 230px; /*position where enlarged image should offset horizontally */
z-index: 50;
}

</style>

html代码：

<div class="gallerycontainer">
<a class="thumbnail" href="#thumb"><img src="CSStestpicture/scenery1s.jpg" width="80" height="60" /><span><img src="CSStestpicture/scenery1.gif" /><br />动画欣赏</span></a>
<a class="thumbnail" href="#thumb"><img src="CSStestpicture/scenery2s.jpg" width="80" height="60" /><span><img src="CSStestpicture/scenery2.gif" /><br />动画欣赏</span></a>
<br />
<a class="thumbnail" href="#thumb"><img src="CSStestpicture/scenery3s.jpg" width="80" height="60" /><span><img src="CSStestpicture/scenery3.gif" /><br />动画欣赏</span></a>
<a class="thumbnail" href="#thumb"><img src="CSStestpicture/scenery4s.jpg" width="80" height="60" /><span><img src="CSStestpicture/scenery4.gif" /><br />动画欣赏</span></a>
<br />
<a class="thumbnail" href="#thumb">动画欣赏5<span><img src="CSStestpicture/scenery5.gif" /><br />动画欣赏</span></a>
<br />
<a class="thumbnail" href="#thumb">动画欣赏6<span><img src="CSStestpicture/scenery6.gif" /><br />动画欣赏</span></a>

</div>