function addBookToLibrary(){
    let form = document.getElementById('form');

    const submitButton = document.getElementById('submit');
    submitButton.addEventListener('click', submit)

    alert('Please enter information about the book into the form.');
    form.hidden = false;
}

function clearLibraryContainer(){
    let libElement = document.getElementById('library');
    if(libElement.hasChildNodes()){
        libElement.childNodes.forEach(function(childNode){
            childNode.remove();
        });
    }
    return;
}

function submit() {
    let title = document.getElementById('title'),
        author = document.getElementById('author'),
        numPages = document.getElementById('numPages'),
        readOrNot = document.getElementsByName('readAnswer');

    try {
        if(title.value == '' || author.value == '' || numPages == ''){
            throw new emptyException('You cannot leave any fields blank.');
        }
    }
    catch(err){
        alert(err.message);
        return;
    }

    readOrNot.forEach(function(radioButton){
        if(radioButton.checked){
            readOrNot = radioButton.value;
        }
    });

    library.push(new Book(title.value, author.value, numPages.value, readOrNot));

    title.value = '';
    author.value = '';
    numPages.value = '';
    form.hidden = true;
    clearLibraryContainer();
    render();
    return;
}
return;