代码如下：
<style> <!-- .mouseBeOffMe { border-top: 10px solid #000000; border-bottom: 10px solid #000000; border-left: 6px solid #000000; border-right: 10px solid #000000; } .mouseBeOnMe { border-top: 6px solid #000000; border-bottom: 14px solid #000000; border-left: 10px solid #000000; border-right: 6px solid #000000; } .mouseBeDown { border-top: 13px solid #000000; border-bottom: 7px solid #000000; border-left: 10px solid #000000; border-right: 6px solid #000000; } .mouseBeUp { border-top: 10px solid #000000; border-bottom: 10px solid #000000; border-left: 10px solid #000000; border-right: 6px solid #000000; } //--> </style> <img src = "images/1.gif" width = "90" height = "90" border = "0" class = "mouseBeOffMe" onmouseover = "this.className='mouseBeOnMe'" onmousedown = "this.className='mouseBeDown'" onmouseup = "this.className='mouseBeUp'" onmouseout = "this.className='mouseBeOffMe'"> <img src = "images/2.gif" width = "90" height = "90" border = "0" class = "mouseBeOffMe" onmouseover = "this.className='mouseBeOnMe'" onmousedown = "this.className='mouseBeDown'" onmouseup = "this.className='mouseBeUp'" onmouseout = "this.className='mouseBeOffMe'"> <img src = "images/3.gif" width = "90" height = "90" border = "0" class = "mouseBeOffMe" onmouseover = "this.className='mouseBeOnMe'" onmousedown = "this.className='mouseBeDown'" onmouseup = "this.className='mouseBeUp'" onmouseout = "this.className='mouseBeOffMe'">