function showContentBox() {
    let elem = document.getElementById('backgroundTint');
    elem.classList.remove('hidden');
    elem.classList.add('shown');

    elem = document.getElementById('contentBox');
    elem.classList.remove('hidden');
    elem.classList.add('shown');
}

function hideContentBox() {
    let elem = document.getElementById('backgroundTint');
    elem.classList.remove('shown');
    elem.classList.add('hidden');

    elem = document.getElementById('contentBox');
    elem.classList.remove('shown');
    elem.classList.add('hidden');
}

function showForm() {
    let newEntryBtn = document.getElementById('newEntryBtn');
    newEntryBtn.style.display = 'none';

    showContentBox();
    let contentBox = document.getElementById('contentBox');
    while (contentBox.firstChild)
        contentBox.removeChild(contentBox.firstChild);

    contentBox.appendChild(elementFromHTML(baseFormFields));
    return contentBox;
}

function hideForm() {
    let newEntryBtn = document.getElementById('newEntryBtn');
    newEntryBtn.style.display = 'inline';

    let contentBox = document.getElementById('contentBox');
    while (contentBox.firstChild)
        contentBox.removeChild(contentBox.firstChild);

    hideContentBox();
}

function showEditForm() {
    let contentBox = showForm();
    contentBox.firstChild.appendChild(elementFromHTML(formEditButtons));
    contentBox.firstChild.action = '/api/update';
}

function showCreateForm() {
    let contentBox = showForm();
    contentBox.firstChild.appendChild(elementFromHTML(formCreateButtons));
    contentBox.firstChild.action = '/api/add';
    document.getElementById('formServiceId').disabled = false;
}