DIV中的内容 怎么让其垂直居中?????
<!DOCTYPE   html   PUBLIC    "-//W3C//DTD   XHTML   1.0   Transitional//EN "    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">  
  <html   xmlns= "http://www.w3.org/1999/xhtml "   lang= "gb2312 "   xml:lang= "gb2312 ">  
  <head>  
  <title> Down   CSS </title>  
  <meta   http-equiv= "Content-Type "   content= "text/html;   charset=gb2312 "   />  
  <script   type= "text/javascript "   src= "chrome.js ">  
  </script>  
  <style   type= "text/css ">  
  <!-- 
 .chromestyle   {width:760px;   background-color:#165AB3;   /*font-weight:bold;*/} 
 .chromestyle   ul   li   {   display:inline;}    <!--让LI没有黑点横向排列-->    
 .chromestyle   ul   li   a   { 
 color:#494949; 
 padding:4px   7px; 
 margin:0; 
 text-decoration:none; 
 border-right:1px   solid   #DADADA; 
 }     
 .chromestyle   ul   li   a[rel]:after{ 
 content: "v "; 
 }   
 .chromestyle:after{   
 content: ". "; 
 display:block; 
 height:0; 
 clear:both; 
 visibility:hidden; 
 } 
 .dropmenudiv   { 
 position:absolute; 
 top:0; 
 border:1px   solid   #165AB3;   /*边框*/ 
 border-bottom-width:0; 
 font:normal   12px   Verdana; 
 line-height:18px; 
 z-index:100; 
 background-color:#5293d1; 
 width:100px; 
 visibility:hidden; 
 filter:progid:DXImageTransform.Microsoft.Shadow(color=#CACACA,direction=135,strength=4); 
 }   
 .dropmenudiv   a{ 
 width:auto; 
 display:block; 
 text-align:3x; 
 padding:2px   0; 
 border-bottom:1px   solid   #165AB3;/*设置对象下边框的样式*/ 
 text-decoration:none; 
 font-weight:bold; 
 color:#FFFFFF; 
 }   
 *   html   .dropmenudiv   a{ 
 width:100%; 
 }   
 .dropmenudiv   a:hover 
 { 
 background-color:#1d7fdb; 
 } 
 body   { 
 	font-size:   12px; 
 	text-decoration:   none; 
 	margin:   0px; 
 	text-align:center; 
 }     
 a:link   { 
 	color:   #FFFFFF; 
 	text-decoration:   none; 
 }   
 a:visited   { 
       color:   #FFFFFF; 
       text-decoration:   none; 
 }   
 a:hover   { 
 	text-decoration:   none; 
 	color:#FFFF00 
 }   
 a:active   { 
 	color:   #FFFFFF; 
 	text-decoration:   none;  	 
 }   
 a.hidden   { 
       color:   #FFFFFF; 
 }     
 -->  
  </style>  
  </head>    
  <body>    
  <!--   主菜单   -->   			 
  <div   id= "chromemenu "   class= "chromestyle ">  
 	 <ul>  
 		 <li>  <a   href= "# "> 首页   | </a>  </li>  
 		 <li>  <a   href= "# "   rel= "dropmenu1 "> 新闻中心   | </a>  </li>  
 		 <li>  <a   href= "# "   rel= "dropmenu2 "> 产品方案   | </a>  </li>  
 		 <li>  <a   href= "# "   rel= "dropmenu3 "> 服务支持   | </a>  </li>  
 		 <li>  <a   href= "# "   rel= "dropm