function startApp() {
    //clear user auth data
    sessionStorage.clear()

    showHideMenuLinks()

    showView('viewHome')

    //bind navigation menu links
    $('#linkHome').click(showHomeView)
    $('#linkLogin').click(showLoginView)
    $('#linkRegister').click(showRegisterView)
    $('#linkListAds').click(listAds)
    $('#linkCreateAd').click(showCreateAdView)
    $('#linkLogout').click(logoutUser)

    //bind the form submit buttons
    $('#formLogin').submit(loginUser)
    $('#formRegister').submit(registerUser)
    $('#buttonCreateAd').click(createAd)
    $('#buttonEditAd').click(editAd)

    //bind the info/error boxes: hide on click
    $('#infoBox, #errorBox').click(function () {
        $(this).fadeOut()
    })

    // Attach AJAX "loading" event listener
    $(document).on({
        ajaxStart: function () {
            $("#loadingBox").show()
        },
        ajaxStop: function () {
            $("#loadingBox").hide()
        }
    });


    const kinveyBaseUrl = "https://baas.kinvey.com/";
    const kinveyAppKey = "kid_HJbWZ-hMe";
    const kinveyAppSecret = "2230ec6d6ff848a3b9f0c65ae46f7b09";
    const kinveyAppAuthHeaders = {
        'Authorization': "Basic " + btoa(kinveyAppKey + ":" + kinveyAppSecret),
        'Content-type': "application/json"
    };

    function showHideMenuLinks() {
        $('#menu a').hide()
        if (sessionStorage.getItem('authToken')) {
          //  setUsernameInLink()
            //logged in user
            $('#linkHome').show()
            $('#linkListAds').show()
            $('#linkCreateAd').show()
            $('#linkLogout').show()
            $('#loggedInUser').show()
        } else {
            //no user logged in
            $('#linkHome').show()
            $('#linkLogin').show()
            $('#linkRegister').show()
        }
    }

    function showView(viewName) {
        // Hide all views and show the selected view only
        $('main > section').hide();
        $('#' + viewName).show();
    }

    function showHomeView(){
        showView('viewHome')
    }

    function showLoginView(){
        showView('viewLogin')
        $('#formLogin').trigger('reset')
    }

    function showRegisterView(){
        showView('viewRegister')
        $('#formRegister').trigger('reset')
    }

    function registerUser(event){
        event.preventDefault()

        let data = {
            username: $('#formRegister input[name=username]').val(),
            password: $('#formRegister input[name=passwd]').val()
        }

        $.ajax({
            method: "POST",
            url: kinveyBaseUrl + 'user/' + kinveyAppKey + '/',
            headers: kinveyAppAuthHeaders,
            data: JSON.stringify(data),
            success: registerUserSuccess,
            error: handleAjaxError
        })

        function registerUserSuccess(userInfo){
            saveAuthInSession(userInfo)
            showHideMenuLinks()
            listAds()
            showInfo('User registration successful.')
        }

    }


    function saveAuthInSession(userInfo){
        sessionStorage.setItem('username', userInfo.username)
        sessionStorage.setItem('authToken', userInfo._kmd.authtoken)
        sessionStorage.setItem('userId', userInfo._id)
        $('#loggedInUSer').text('Welcome, ' + userInfo.username)
    }


    function showInfo(msg){
        $('#infoBox').text(msg)
        setTimeout(function () {
            $('#infoBox').fadeOut()
        }, 3000)
    }


    function handleAjaxError(error){
        $('#errorBox').text('Error: ' + error)
    }

    function listAds(){

    }

    function showCreateAdView(){

    }

    function logoutUser(){

    }

    function loginUser(){

    }

    function createAd(){

    }

    function editAd(){

    }
}