咨询一个问题：用ulli写的导航栏，下拉菜单怎么不显示？谢谢各位_html/css_WEB-ITnose

CSS code :

* {
margin:0;
padding:0;
list-style:none;
}
body {
background:#f0f0f0;
color:#999;
font-size:12px;
font-family:"Lucida Grande",Arial,sans-serif;
line-height:1.5em;
overflow-y:auto;
overflow-x:auto;
}
img {
border:0;
}
a {
color:write;text-decoration:none;
bblr:expression(this.onFocus=this.blur());
outline:none;
}
li {list-style:none;}

.logo_box{ width:399px; height:100px; align:left;float:left;}
.logo_box a{font-size:1.2em;Line-height:1.8em}
.top_right{ width:500px; float:right;}
.hydl_box{ width:500px; text-align:right; height:12px; line-height:12px; color:#999999;}
.hydl_box a{color:#999999;}


.clearfix:after {
content:".";
display:block;
height:0;
clear:both;
visibility:hidden;
}
.topNav {
position:relative;
z-index:1;
height:40px;
line-height:40px;
background: url(../images/nav_bg.JPG) repeat-x top left;
font-family:"Lucida Grande",Arial,sans-serif;
font-size:12px;
}
.topNav-width {
width:1640PX;
height:40px;
margin:0 auto;
}
.topNav h3 {
font-weight:normal;
font-size:12px;

}
.topNav .tnLeft {
float:left; ;
}
.topNav li {
float:left;
position:relative;
}
.topNav li h3 {
float:center;
font-weight:normal;
font-size:12px;
}
.topNav li h3 a {
display:inline-block;
*display:inline;
zoom:1;
font-size:12px;
height:14px;
line-height:14px;
padding:13px 20px;
color:white
}
.topNav li h3 a i {
display:inline-block;
width:8px;
height:5px;
margin:0 0 0 5px;
overflow:hidden;
vertical-align:middle;
font-size:12px;
line-height:13px;
background:url(images/nav_bg.JPG) 0 -61px no-repeat;
}
.topNav li h3 a:hover,.topNav li.on h3 a {
background:#1C86EE;

}
.topNav .welcome {
padding-right:15px;
color:white;
}
.topNav .welcome a {
color:white;
}
.topNav li ul {
display:none;
position:relative;
left:0;
border:1px solid #CDC9C9;
border-top:0;
background:#1C86EE;
-moz-box-shadow:3px 3px 3px rgba(0,0,0,.1);
-webkit-box-shadow:3px 3px 3px rgba(0,0,0,.1);
box-shadow:3px 3px 3px rgba(0,0,0,.1);
}
.topNav li ul li {
line-height:31px;
}
.topNav li ul li a {
display:block;
color:white;
padding:0 15px;
}
.topNav li ul li a:hover {
background:#CFCFCF;
color:white;
}
.topNav li ul li a span {
color:white;
margin-left:5px;
}
/*
.body{
position:relative;
}
*/
.foot_box{ width:100%; background:url(../images/foot_bg_03.jpg) repeat-x; height:36px;}
.foot_con{ width:1000px; margin:0 auto; text-align:right; color:#FFF; height:32px; line-height:32px;}Html code：







2. li，或子集ul上缺少标志class。

                
Home Page
                
Report Management
                    
                        
Weekly
                        
Monthly
                    

3. css，li要展开的话，必须修改。

 .topNav li ul li{line-height:31px;float: none;}

最后完整的html

可能是content没写宽度的原因。

.content{width:900px;}