4、动画菜单
下面我们来实现如下图所示的动画菜单。当鼠标移入到菜单上，以动画的形式出现二级菜单。
css代码如下：
html, body, ul, li {padding:0; margin:0;}
body {font:10pt;}
ul,li {list-style-type:none; text-transform:capitalize;}
.clear {clear:both; *display:inline;/*IE only*/}
/*menu*/
#menu {margin:100px auto; display:block; width:1000px; height:34px;}
#nav {display:block;}
#nav .mainlevel {float:left; background:#3f240e; text-align:center; display:block;}
#nav .mainlevel a {color:#fff; text-decoration:none; line-height:34px; height:34px; text-align:center; padding:0 20px; display:block; _width:48px;}
#nav .mainlevel a:hover {color:#3f240e; text-decoration:none; background:#678900 url(images/slide-pannel_14.png) 0 0 repeat-x;}
#nav .mainlevel ul {position:absolute; display:none; *width:2000px;/*IE is great need, width>=li.length*/}
#nav .mainlevel li {float:left; background:#3f240e;}
#nav .mainlevel li a {padding:0 12px; line-height:24px; height:24px; display:block; _padding-bottom:6px;/*IE6 only*/}
#nav .mainlevel li a:hover {color:#3f240e; text-decoration:none; background:#678900 url(images/slide-pannel_14.png) 0 0 repeat-x;}
#nav li a em/*input an em tag as a space*/ {padding:0 3px;}
.note {color:#3f240e; border-right:1px solid #fff; background:#678900 url(images/slide-pannel_14.png) 0 0 repeat-x; display:block; line-height:34px; padding:0 3em;}
.Triangle_con {height:9px; background:url(images/bird.png) 36px 0 no-repeat; display:block; _margin-bottom:-6px;/*IE6 only*/}
.log {margin:100px auto; width:1000px; text-transform:capitalize; line-height:200%;}
使用jquery代码实现动画效果：
