title: Header on specific screen
body: <p>I'm working on an application with React-Native.
  I'm using React-Navigation and In my login and register screens I don't want header to be shown.
  this is what I wrote and it is working:</p>
  
  <pre><code>const Stylelist = StackNavigator({
    Login: { screen: HomeScreen}, // when finish working on homescreen, change back to LoginScreen
    Register: { screen: RegisterScreen},
    Home: { screen: HomeScreen},
  },{headerMode: "none"});
  </code></pre>
  
  <p>Now I'm working on my Homescreen and I want the home screen to have an header.
  How can I enable the header only on the home screen?
  I tried changing "headerMode: 'none'" position but it didn't work.</p>