handleClick() {

    fetch('/backend/login', {
        method: 'POST',
        headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json',
        },
        body: JSON.stringify({
            username: this.state.username,
            password: this.state.password
        })
    })
    .then(response =>{
        if (response.ok) {
            response.json().then(data => {
                sessionStorage.setItem('loggedIn', data.success);
                console.log('login success: ' + sessionStorage.getItem('loggedIn'));
            });
        }
        else {
            console.log('failed');
        }
    })
}

render () {
  <LinkContainer to='/Dashboard'>
    <Button onClick={this.handleClick} type="submit"> Submit />
    </Button>
  </LinkContainer>
}

function requireAuth(nextState, replace) {
if (!(sessionStorage.getItem('loggedIn') === true)) {
   console.log(sessionStorage.getItem('loggedIn'));
      replace({
        pathname: '/',
        state: { nextPathname: nextState.location.pathname }
    });
}
}

ReactDOM.render(
 <Router history={browserHistory}>
    <Route path="/" component={Container}>
        <IndexRoute component={Homepage}/>
        <Route path="dashboard" component={Dashboard} onEnter=
{requireAuth}/>
   </Route>
</Router>