part4.html

<!-- signup function -->
<script>    
    signupButton.addEventListener('click', signup);

    function signup() {
        signupButton.style.display = 'none';
        signupError.style.display = 'none';
        var email = signupEmail.value;
        var password = signupPassword.value;

        firebase.auth().createUserWithEmailAndPassword(email, password)
            .then(function () {
                window.location.replace('./private');
            })
            .catch(function (error) {
                var errorCode = error.code;
                var errorMessage = error.message;
                console.log('Error code: ' + errorCode);
                console.log('Error message: ' + errorMessage);
                signupButton.style.display = 'block';
                signupError.innerText = errorMessage;
                signupError.style.display = 'block';
            });
    }
</script>

<!-- auth state function -->
<script>
    firebase.auth().onAuthStateChanged(function (user) {
        if (user) {
            // User is signed in.
            console.log('User is logged in!');
            console.log('Email: ' + user.email);
            console.log('UID: ' + user.uid);
        } else {
            // User is signed out.
            console.log('No user is logged in');
        }
    });
</script>