这段css排版有什么问题?我看了一下说还可以,我朋友说很菜!!
这段代码可以直接复制运行!!! 
 很完整,没有图片,单个文件!!!!   
 高手帮忙看看,说说这里面都有哪些细节问题?   
 顺便问一下,css中一般都是怎么控制高度的? 
 譬如这个页面中间有三个框,一般怎么把这三个框高度对齐???     
  <!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 ">  
  <head>  
  <meta   http-equiv= "Content-Type "   content= "text/html;   charset=gb2312 "   />  
  <title> 无标题文档 </title>    
  <style   type= "text/css ">    
 body   { 
 	padding-left:   0px; 
 	padding-right:   0px; 
 	background:   #fff; 
 	margin:   0px   auto; 
 	color:   #000; 
 	text-align:   center; 
 	font-size:   12px; 
 }   
 a:link   { 
 	color:   #1f3a87; 
 	text-decoration:   none; 
 }   
 a:visited   { 
 	color:   #83006f; 
 	text-decoration:   none; 
 }   
 a:hover   { 
 	color:   #bc2931;    
 	text-decoration:   underline; 
 }   
 a:active   { 
 	color:   #bc2931 
 	text-decoration:   none; 
 }   
 .dborder   { 
 	border:   #cbcbcb   1px   solid;    
 	background:   #f2f6fb;    
 }   
 #header   { 
 	width:   760px;    
 	height:   60px; 
 }   
 #header   #logo   { 
 	float:   left; 
 	width:   120px; 
 }   
 #header   #navigate   { 
 	float:   left; 
 	width:   620px; 
 	padding-top:   12px; 
 }   
 #header   #navigate   ul   {  	 
 }   
 #header   #navigate   li   { 
 	display:   block; 
 	float:   left; 
 	width:   37px; 
 	list-style-type:   none; 
 	padding-top:20px; 
 }   
 .floatclear   { 
 	clear:   both; 
 }   
 .blockad   { 
 	padding-top:   9px; 
 	padding-bottom:   9px; 
 	width:   760px; 
 	height:   40px; 
 	background:   #f00; 
 }   
 #activebar   { 
 	width:   760px; 
 	height:   60px; 
 }   
 #search   { 
 	float:   left; 
 	width:   200px; 
 }   
 #news   { 
 	float:   left; 
 	width:   300px; 
 }   
 #login   { 
 	float:   left; 
 	width:   250px; 
 }     
 #content   { 
 	width:   760px; 
 }   
 #content   #left   { 
 	float:   left; 
 	width:   556px; 
 }   
 #content   #right   { 
 	float:   right; 
 	width:   196px; 
 }   
 #footer   { 
 	width:   760px;    
 	height:   60px; 
 }   
 .blankline   { 
 	clear:   both; 
 	background:   #fff; 
 	overflow:   hidden; 
 }   
 .bh6   { 
 	height:   6px; 
 }   
 .title   { 
 	height:   20px; 
 	border-bottom:   1px   dashed   #f00; 
 }     
  </style>    
  </head>    
  <body>      
  <div   id= "header "   class= "dborder ">  
        <div   id= "logo "   class= &q