title: clear/reset formData() using javascript
body: <p>I use formData below, and pass the results. But data is duplicated if the user does it more than once. So I have to clear/reset the formData before adding any value.</p>
  
  <p>I can do it one-by-one like f.name = '', I have tons of keys. Is there any better way to solve the problem?</p>
  
  <pre><code>$('input').change(function(){
  // Create a new formdata but at first have to clear/reset it
  var fd = new FormData();
  var f = $.canvasResize('dataURLtoBlob', data);
  f.name = file.name;
  fd.append($('#area input').attr('name'), f);
  })
  </code></pre>