鼠标移到图片后改变图片透明度

<script  type="text/javascript" >$(document).ready(function(){$("img").fadeTo("slow", 0.4); // This sets the opacity of the thumbs to fade down to 40% when the page loads$("img").hover(function(){$(this).fadeTo("slow", 1.0); // This should set the opacity to 100% on hover},function(){   $(this).fadeTo("slow", 0.4); // This should set the opacity back to 40% on mouseout});});</script>

注意使用时需要引入jquery