本特效代码是比较有意思的：

JS半透明效果,鼠标滑过显亮

具体代码如下所示：

<!-- 图片 -->
<img src="http://www.panpan.org/pphome/logo.gif" width="136" border="0" onmouseover="nereidFade(this,100,10,5)" style="FILTER: alpha(opacity=50);" tabIndex=5 onmouseout="nereidFade(this,50,10,5)"/>

<!-- JS代码 -->
<SCRIPT language=JavaScript type=text/JavaScript >
// JavaScript Document
nereidFadeObjects = new Object();
     nereidFadeTimers = new Object();
     function nereidFade(object, destOp, rate, delta){
     if (!document.all)
     return
      if (object != "[object]"){
       setTimeout("nereidFade("+object+","+destOp+","+rate+","+delta+")",0);
       return;
      }
      clearTimeout(nereidFadeTimers[object.sourceIndex]);
      diff = destOp-object.filters.alpha.opacity;
      direction = 1;
      if (object.filters.alpha.opacity > destOp){
       direction = -1;
      }
      delta=Math.min(direction*diff,delta);
      object.filters.alpha.opacity+=direction*delta;
      if (object.filters.alpha.opacity != destOp){
       nereidFadeObjects[object.sourceIndex]=object;
       nereidFadeTimers[object.sourceIndex]=setTimeout("nereidFade(nereidFadeObjects

["+object.sourceIndex+"],"+destOp+","+rate+","+delta+")",rate);
      }
     }
</SCRIPT>

以上代码经过测试