bowd

  initiateTransition: function() {
    // Set the state so that both screens
    // will be rendered.
    this.setState({
      transitionStarted: true,
      transitionDirection: this.state.activeScreen.get('stackIndex') > this.state.screensStackTop.get('stackIndex') ? "back" : "fwd"
    });

    // Schedule a cleanup so that we remove the 
    // previous screen after the transition occurs