function validateNewsLetter() {
    var emailInput = $("newsletterField");
    var feedback = $("feedbackNewLetter");
    
    feedback.innerHTML = "";
    if(!emailInput.value.test("^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}$")) {
	feedback.set("text", "Vueillez entrer une adresse email valide! (ex: jean.dupond@mail.com)");
	return false;
    }
    
    return true;
}