title: How do I make a phone call with nativescript?
body: <p><strong>I want to make a phone call when I press the button.
  I am calling the phone number to the label.
  This is my button ;</strong></p>
  
  <pre><code>&lt;ActionBar&gt;
      &lt;NavigationButton (tap)="onBackTap()" android.systemIcon="ic_menu_back"&gt;&lt;/NavigationButton&gt;
      &lt;Label class="action-bar-title" style="font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 10px;" [text]="item.name"&gt;&lt;/Label&gt;
  &lt;/ActionBar&gt;
  
  &lt;StackLayout&gt;
  &lt;Label class="action-bar-title" style="font-family: Georgia, 'Times New Roman', Times, serif;
          font-size: 10px;" [text]="item.number"&gt;&lt;/Label&gt;
      &lt;Button text="&amp;#xff17b; Call!" (tap)="onTap()" class="my-button"&gt;&lt;/Button&gt;
  &lt;/StackLayout&gt;
  </code></pre>
  
  <p><strong>this is my onTap() method ;</strong></p>
  
  <pre><code>export class ItemDetailComponent implements OnInit {
      item: IDataItem;
  
      constructor(
          private _data: DataService,
          private _route: ActivatedRoute,
          private _routerExtensions: RouterExtensions
      ) { }
  
      ngOnInit(): void {
          const id = +this._route.snapshot.params.id;
          this.item = this._data.getItem(id);
      }
  
      onBackTap(): void {
          this._routerExtensions.back();
      }
      onTap(): void {
  
      }
  }
  </code></pre>
  
  <p><strong>How do I make a phone call ?</strong></p>