title: copying the value of a form's file input field to another form's input field
body: <p>So I have two forms, both have a file type input field and I tried</p>
  
  <pre><code>$('.inputfield1').change(function(){
     var file = $(this).val();
     $('.inputfield2').val(file);
  });
  </code></pre>
  
  <p>but then it doesn't get copied properly and firebug complains about "Security Error" in the error console</p>
  
  <p>what did I do wrong and how can I properly copy the value of a file input field</p>
  
  <p>by the way, the destination form has a target that is set to an iframe (not a different domain) </p>