function onClickButtonSubmit(element, event)
{
  var validity = checkRegisterInputValidity();
	
	if (validity == true)
	{
		var form = document.getElementById("form_newsletter");
		form.submit();
	}
	else
	{
		var elementMessage = document.getElementById("validity_message");
		setData(elementMessage, validityMessage);
	}	
}

function checkRegisterInputValidity()
{
	var input_lastname = document.getElementById("newsletter_last_name");
	var input_firstname = document.getElementById("newsletter_first_name");
	var input_email = document.getElementById("newsletter_email");

	var firstname = input_firstname.value;	
	var lastname = input_lastname.value;
	var email = input_email.value;

	if (!lastname || lastname.length == 0)
	{
		validityMessage = "Veuillez entrer votre nom";
		return false;
	}
	
	if (!firstname || firstname.length == 0)
	{
		validityMessage = "Veullez entrer votre pr\351nom";
		return false;
	}

	if (!email || email.length == 0 || !checkMail(email))
	{
		validityMessage = "Veuillez entrez votre adresse email";
		return false;
	}
		
	return true;
}

function checkMail(email)
{
	var x = email;
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(x)) 
		return true;
	else 
		return false;
}