title: why not get POST parameters in ajax POST of jQuery
body: <p>The code is listed below:</p>
  
  <pre><code>    $.ajax({
       type: "POST",
       url: "http://localhost:3000/rcm/global_config/update",    
       data: {k: 'sdfa', v: 'dsfas'},
       success: function(data, textStatus, XMLHttpRequest){
         alert("数据更新成功");
       },
       error: function(xhr,textStatus, errorThrown){
         alert("数据更新失败，请刷新回滚");
       }
      });
  </code></pre>
  
  <p>In the server i can not get post parameters, and then i tamper the request sent by ajax, it doesn't send the data params at all. i don't know where i am wrong.</p>
  
  <p>thank you in advance.</p>