title: Prolog XPCE how to get multiple values from text item?
body: <p>I have a dialog which contains multiple text item elements and a button. How can i 
  retrieve the values and use them?  </p>
  
  <pre><code>new(D, dialog('Add a recipe')),
  send(D, append(new(NameItem,   text_item('Name')))),
  send(D, append(new(InstItem,   text_item('Instruction')))),
  send(D, append(new(IngrItem,   text_item('Ingredients')))),
  send(D, append(new(TimeItem,   text_item('Time')))),
  send(D, append(button('Store', message(D, return, '1')))),
  get(D, confirm, Rvalue),
  write(NameItem), nl,
  write(InstItem), nl,
  write(IngrItem), nl,
  write(TimeItem), nl,
  free(D),
  </code></pre>