<h3>Upload file</h3>
<form enctype="multipart/form-data" method="post">
  <div>
    <label for="picked">Choose file to upload</label>
    <div>
      <input type="file" id="picked" #picked
        (click)="message=''"
        (change)="onPicked(picked)">
    </div>
  </div>
  <p *ngIf="message">{{message}}</p>
</form>
