title: where to add Access-Control-Allow-Headers to the response in ajax call
body: <p><strong>My Code:</strong></p>
  
  <pre><code>  $.ajax({
              origin: "*",
              url: 'http://SP/api/test',
              type: 'get',
              dataType: 'jsonp',
              crossDomain: true,
              beforeSend: function (xhr) {
                  xhr.setRequestHeader("API_KEY", "XX");
                  xhr.setRequestHeader("Authorization", "XX";
              },
              success: function (data) {          
                  });
              },
              error: function (y) {
  
              }
          });
  </code></pre>
  
  <p><strong>Request Headers:</strong></p>
  
  <pre><code>GET http://SP/api/testcallback=jQuery22406877213234276709_1489930192633&amp;_=1489930192634 HTTP/1.1Host:http://SP/
  Connection: keep-alive
  User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36
  Accept: */*
  
  Referer: http://SP/api/test
  Accept-Encoding: gzip, deflate, sdch
  Accept-Language: en-US,en;q=0.8
  </code></pre>
  
  <p>I believe that I should add <strong>Access-Control-Allow-Headers</strong> but I didn't know where to add.</p>