title: How to pass a parameter from a viewmodel to its parent viewmodel
body: <p>First View is a listview including some items.</p>
  
  <p>eg. item0, item1, item2</p>
  
  <p>When click a "new" button, the second view will be shown.</p>
  
  <p>Then click a "save" button and input a name(eg. item3). The "item3" will be save in seconde viewmodel</p>
  
  <p>After saving success. The first view will refresh and show "item3"</p>
  
  <p>How to pass name "item3" from second viewmodel to first viewmodel for showing in first view?</p>