title: JavaScript jQuery AJAX POST data error
body: <p>I am trying to send a post param. to <code>request.php</code> but it returns that the post param. are empty.</p>
  
  <pre><code>&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"&gt;&lt;/script&gt;
  $.ajax({
      url: "request.php",
      type: "POST",
      data: "{key:'123', action:'getorders'}",
      contentType: "multipart/form-data",
      complete: alert("complete"),
      success: function(data) {
          alert(data);
      },
      error: alert("error")
  });
  </code></pre>