<style type="text/css">
<!--
.thumbnail {
 POSITION: relative
}
.thumbnail:hover {
 Z-INDEX: 50; BACKGROUND-COLOR: transparent
}
.thumbnail SPAN {
 BORDER-RIGHT: gray 1px dashed; PADDING-RIGHT: 1px; BORDER-TOP: gray 1px dashed; PADDING-LEFT: 1px; LEFT: -1000px; VISIBILITY: hidden; PADDING-BOTTOM: 1px; BORDER-LEFT: gray 1px dashed; COLOR: black; PADDING-TOP: 1px; BORDER-BOTTOM: gray 1px dashed; POSITION: absolute; BACKGROUND-COLOR: lightyellow; TEXT-DECORATION: none
}
.thumbnail SPAN IMG {
 BORDER-TOP-WIDTH: 0px; PADDING-RIGHT: 2px; PADDING-LEFT: 2px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px; BORDER-RIGHT-WIDTH: 0px
}
.thumbnail:hover SPAN {
 LEFT: 100px; VISIBILITY: visible; TOP: 0px
}
-->
</style>
其实是通过一个Style来实现的，运行速度极快，加入以上Style之后，看以下例子：

<a href="../project/2009062774813505.jpg" class=thumbnail  target="_blank" title="点击放大">2009062774813505.jpg<SPAN><IMG height=100 src="../project/2009062774813505.jpg" border=0></SPAN></a>