错在哪?不符合W3C标准
一头雾水了。。。顺便问问哪可以学HTML的W3C标准   谢谢   
  <!DOCTYPE   html   PUBLIC    "-//W3C//DTD   XHTML   1.1//EN "    "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd ">  
  <html   xmlns= "http://www.w3.org/1999/xhtml ">  
  <head>  
  <title>  
 请登陆 </title>  
  </head>  
  <body>  
  <img   src= "bookmark.gif "   alt= "logo "   style= "float:left; "   />  
  <h1   > PHP   BookMark </h1>  
  <hr   />  
  <a   href= "register_form.php "> 注册 </a>  
  <form   method= "post "   action= "member.php ">  
        <table   style= 'background:#cccccc '>  
           <tr>    
                 <td   colspan= "2 "> 请登陆 </td>  </tr>  
           <tr>  
                 <td> 用户: </td>  
                 <td>  <input   type= 'text '   name= 'username '   />  </td>  </tr>  
           <tr>  
                 <td> 密码: </td>  
                 <td>  <input   type= 'password '   name= 'passwd '   />  </td>  </tr>    
           <tr>  
                 <td   colspan= "2 "   align= 'center '>  
                 <input   type= 'submit '   value= '登陆 '   />  </td>  </tr>  
           <tr>  
                 <td   colspan= "2 ">  <a   href= 'forgot_form.php '> 忘记密码? </a>  </td>  
           </tr>  
     </table>  
     </form>    
     </body>  
  </html>  
------解决方案--------------------http://www.w3cn.org