document.getElementById("instructor_application_head_portrait").onchange = function () {

  if ($('#head_image').is(":hidden")) {
    $('#head_image').show()
  }

  var reader = new FileReader();

  reader.onload = function (e) {
    document.getElementById("head_image").src = e.target.result;
  };

  reader.readAsDataURL(this.files[0]);
};