要完成此效果把如下代码加入到区域中 <script language=JavaScript> var d=0 function JM_fade(ob){ if (d==0) {ob.filters.alpha.opacity+=1} else {ob.filters.alpha.opacity-=1} if (ob.filters.alpha.opacity==100){d=1;} else if (ob.filters.alpha.opacity==0){d=0} } setInterval("JM_fade(u)",10) </script>