function subscribeToNewletter() {
    new Ajax.Updater('subscribe_message', 'ajax_subscribe.php', {
	    parameters: { email: $('subscribe_email').value }
	});
}

function unsubscribeFromNewletter() {
    new Ajax.Updater('unsubscribe_message', 'ajax_unsubscribe.php', {
	    parameters: { email: $('unsubscribe_email').value }
	});
}

function validateFields() {
    var from_name = document.getElementById('from_name');
    var from_email = document.getElementById('from_email');
    var subject = document.getElementById('subject');
    var body = document.getElementById('body');
    if(from_name.value != '' && from_email.value != '' && subject.value != '' && body.value != '') {
	return true;
    }
    alert('All fields are required');
    return false;
}