<h2>Upload a file</h2>
<form enctype="multipart/form-data" method="post">
  <div>
    <label for="picked">Choose a file to upload:</label>
    <input type="file"
           id="picked"
           #picked
           (click)="message=''"
           (change)="onPicked(picked)">

  </div>
  <p *ngIf="message">{{message}}</p>
</form>
