function showRegister() {
    var element = document.getElementById("user_register");
    if (element.style.display = 'none') {
        document.getElementById("user_login").style.display = 'none';
        $('#user_login').hide(500);        
        $(element).show(200);
        //element.style.display = 'block';
        document.getElementById("login_title").innerHTML = 'Registreren';
    }
}

function showLogin() {
    var element = document.getElementById("user_login");
    //$(element).show(1000);
    //element.style.display = 'block';  
    //document.getElementById("user_register").style.display = 'none';
    $('#user_register').hide(200);
    document.getElementById("login_title").innerHTML = 'Inloggen';
    $(element).show(500);
}