js鼠标点击图片切换效果实现代码

<div id="menuWrapper" class="menuWrapper bg1">  <ul class="menu" id="menu">  <li class="bg1" style="background-position:0 0;">  <a id="bg1" href="#">迈瑞宝</a>  <ul class="sub1" style="background-position:0 0;">  <li><a href="#">报价：11.99-23.69万</a></li>  <li><a href="#">车身结构：三箱</a></li>  <li><a href="#">油耗：8.3-12.0L</a></li>  </ul>  </li>  <li class="bg1" style="background-position:-266px 0px;">  <a id="bg2" href="#">索纳塔8</a>  <ul class="sub2" style="background-position:-266px 0;">  <li><a href="#">报价：13.39-22.59万</a></li>  <li><a href="#">车身结构：三箱</a></li>  <li><a href="#">油耗：9.0-12.0L</a></li>  </ul>  </li>  <li class="last bg1" style="background-position:-532px 0px;">  <a id="bg3" href="#">K5</a>  <ul class="sub3" style="background-position:-266px 0;">  <li><a href="#">报价：10.88-25.58万</a></li>  <li><a href="#">车身结构：三箱</a></li>  <li><a href="#">油耗：8.4-13.0L</a></li>  </ul>  </li>  </ul>  </div>

ul.menu > li > a{ float:left; width:265px; height:50px; margin-top:450px; text-align:center; line-height:50px; color:#ddd; background-color:#333; letter-spacing:1px; cursor:pointer; text-decoration:none; text-shadow:0px 0px 1px #fff;}ul.menu > li ul{ list-style:none; float:left; margin-top:-180px; width:100%; height:110px; padding-top:20px; background-repeat:no-repeat; background-color:transparent;}ul.menu > li ul li{ display:none;} ul.menu > li ul.sub1 {  background-image: url('../img/bg1sub.png'); } ul.menu > li ul.sub2 {  background-image: url('../img/bg2sub.png'); }ul.menu > li ul.sub3{ background-image:url(../img/bg3sub.png);}ul.menu > li ul li a{ color:#fff; text-decoration:none; line-height:30px; margin-left:20px; text-shadow:1px 1px 1px #444; font-size:11px;}ul.menu > li ul li a:hover{ border-bottom:1px dotted #fff;}ul.menu > li ul.sub1 li{ display:block;}

if (!document.defaultView || !document.defaultView.getComputedStyle) { // IE6-IE8  var oldCurCSS = jQuery.curCSS;  jQuery.curCSS = function (elem, name, force) {   if (name === 'background-position') {    name = 'backgroundPosition';   }   if (name !== 'backgroundPosition' || !elem.currentStyle || elem.currentStyle[name]) {    return oldCurCSS.apply(this, arguments);   }   var style = elem.style;   if (!force && style && style[name]) {    return style[name];   }   return oldCurCSS(elem, 'backgroundPositionX', force) + ' ' + oldCurCSS(elem, 'backgroundPositionY', force);  }; } var oldAnim = $.fn.animate; $.fn.animate = function (prop) {  if ('background-position' in prop) {   prop.backgroundPosition = prop['background-position'];   delete prop['background-position'];  }  if ('backgroundPosition' in prop) {   prop.backgroundPosition = '(' + prop.backgroundPosition;  }  return oldAnim.apply(this, arguments); }; function toArray(strg) {  strg = strg.replace(/left|top/g, '0px');  strg = strg.replace(/right|bottom/g, '100%');  strg = strg.replace(/([0-9/.]+)(/s|/)|$)/g, "$1px$2");  var res = strg.match(/(-?[0-9/.]+)(px|/%|em|pt)/s(-?[0-9/.]+)(px|/%|em|pt)/);  return [parseFloat(res[1], 10), res[2], parseFloat(res[3], 10), res[4]]; }