function attachEvents() {

    let username = 'guest';
    let password = 'g';
    let base64encode = btoa(username + ':' + password);
    let authorization = {"Authorization": "Basic " + base64encode};

    let countriesInDataBase = [];
    loadData();

    $('#addBtn').on('click', addCountry);
    $('#deleteBtn').on('click', deleteCountry);

    function addCountry() {
        let name = $('#countryInput').val();

        if (name.length > 0 && !countriesInDataBase.includes(name)) {

            let jsonData = JSON.stringify({name: name});

            countriesInDataBase.push(name);

            $.ajax({
                method: 'POST',
                url: `https://baas.kinvey.com/appdata/kid_HJxYjhw9z/countries`,
                headers: authorization,
                data: jsonData,
                contentType: 'application/json'
            }).then(appendCountry).catch(handleError);

            function appendCountry() {
                $('#countries').append($(`<option>${name}</option>`));
                $('#func').text(`${name} added!`).fadeIn(300).fadeOut(2000);
            }
        } else {
            $('#func').text(`Invalid country!`).fadeIn(300).fadeOut(2000);
        }
        $('#countryInput').val('');
    }

    function deleteCountry() {
        let selected = $('#countries').find(':selected').val();
        let idToDelete;
        $.ajax({
            method: 'GET',
            url: `https://baas.kinvey.com/appdata/kid_HJxYjhw9z/countries`,
            headers: authorization
        }).then(findAndDeleteCountry).catch(handleError);

        function findAndDeleteCountry(res) {
            for(let country of res){
                if(country.name = selected){
                    idToDelete = country._id;
                    break;
                }
            }
            $.ajax({
                method: 'DELETE',
                url: `https://baas.kinvey.com/appdata/kid_HJxYjhw9z/countries/${idToDelete}`,
                headers: authorization,
                contentType: "application/json",
            }).then().catch(handleError)
        }
    }

    function loadData() {
        $.ajax({
            method: 'GET',
            url: `https://baas.kinvey.com/appdata/kid_HJxYjhw9z/countries`,
            headers: authorization
        }).then(addCountries).catch(handleError);

        function addCountries(res) {
            for (let country of res) {
                $('#countries').append($(`<option>${country.name}</option>`));
                countriesInDataBase.push(country.name);
            }
        }
    }

    function handleError(err) {
        console.log('Error: ' + err.status + " " + err.statusText)
    }
}