Login Function

const logIn = (email, password) => {
    $.post(server_addr + '/login', {
        email: email,
        password: password
    }, (data) => {
        authToken = data.token;
        $('#userName').html(data.user.name);
        $('#regLogIn').hide();
        $('#afterLogIn').show();
        connectWebSocket(data.user._id);
    }).fail((error) => {
        let msg = JSON.parse(error.responseText)['message'];
        dialog.showErrorBox('Login Failed!', msg);
    });
};