用虚线做的表格[网页特效]

不知道你见过没有，这个特效是把网页中图片的默认alt的提示去掉

<img src="https://images.downcodes.com/u/info_img/2009-06/18/9597_logo.gif" alt="建站学院1号站"> <img src="https://images.downcodes.com/u/info_img/2009-06/18/9597_logo.gif" alt="建站学院2号站"> <img src="https://images.downcodes.com/u/info_img/2009-06/18/9597_logo.gif" alt="建站学院3号站"> <div style="visibility:hidden;border:0px solid #000000;background-color:#333333;font-size:12px;color:#6699cc;position:absolute;" id=altlayer></div> <script> <span class="visiblesaf0">do***ent.body.onmousemove=quickalt</span>; function quickalt() { if (<span class="visiblesaf1">ev***.srcElement.hint</span>)<span class="visiblesaf3">ev***.srcElement.alt</span>=<span class="visiblesaf1">ev***.srcElement.hint</span>; if(<span class="visiblesaf3">ev***.srcElement.alt</span> && <span class="visiblesaf3">ev***.srcElement.alt</span>!='') { <span class="visiblesaf1">ev***.srcElement.hint</span>=<span class="visiblesaf3">ev***.srcElement.alt</span>; <span class="visiblesaf6">al***yer.style.visibility=</span>'visible'; <span class="visiblesaf7">al***yer.style.left=event.x-1</span>; <span class="visiblesaf8">al***yer.style.top=event.y</span>+16; altlayer.innerHTML=<span class="visiblesaf1">ev***.srcElement.hint</span> <span class="visiblesaf3">ev***.srcElement.alt</span>=""; } else <span class="visiblesaf6">al***yer.style.visibility=</span>'hidden';} </script>