title: Multipart/form-data with iframe
body: <p>Following my code:</p>
  
  <pre><code>var formElement = document.getElementById("myFormElement");
  var oReq = new XMLHttpRequest();
  oReq.open("POST", "submitform.php");
  oReq.send(new FormData(formElement));
  </code></pre>
  
  <p>The form has two fields, the first is the input field (# I_F), the second a text field (# S_T). How to get the same result with an iframe?</p>