大家来帮我看看这个简单的问题啊.在线等.

源码如下,如果我在文本框输入比如aaaa,为什么不会向服务提交,我想不管输入什么值,都提交,应该怎么做.<html>
   <head>
      <meta HTTP-EQUIV='Pragma' CONTENT='no-cache'>
      <meta http-equiv='Content-Type' content='text/html; charset=iso-8859-1'>
      <link rel="stylesheet" href='stylemain.css' type='text/css'>
         <link rel="stylesheet" href='colors.css' type='text/css'>   </head>
   <body>
         <form method='post' ENCTYPE='multipart/form-data' action='upload.cgi'>
  <table border="0" cellpadding="0" cellspacing="0">          
             <tr>
                  
      <td width="220" height="40">&nbsp;</td>
                  <td><input type='file' name='filename' size='45'></td>
               </tr>
    </table>         
            <p align="left"><input type='submit' value='Update Firmware'></p>
         </form>
   </body>
</html>