function updateNewsletter(){
	if ($('newsletter_dump')){
		$('newsletter_dump').remove();
	}
	newsletterParam = $('newsletter_form').serialize(true);
	newsletterParam.template_output = 'box/plugin_newsletter';
	
	if( !validateEmail(document.getElementById('nl_email').value) )
	{
		alert('Please enter a valid email address.');
		return false;
	}
	
	new Ajax.Updater('newsletter_form_holder', 'index.php', {
		parameters: newsletterParam,
		evalScripts: true
	});
}

function validateEmail(email){
	var emailRegEx = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

	if(email.match(emailRegEx)){
		return true;
	}else{
		return false;
	}
}