/* Newsletter subscribe / unsubscribe form validation. */
var NewsletterValidation = new function() {
	/**
	 * @method isValidEmail - Returns true if email is valid.
	 * Regex is from http://www.javascriptkit.com/script/script2/acheck.shtml.
	 * @author gregs 2009-09-22
	 */
	function isValidEmail(email) {
		var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
		return filter.test(email);
	};
	
	return {
		
		/**
		 * @method validateSubscribeForm - Validations subscription form.
		 * Fires alert() with error message if form is not valid.
		 * 
		 * @param {Form} form - The form DOM element to look in for field values.
		 * 
		 * @return {Boolean} true if form is valid. False if not.
		 * @author gregs 2009-09-22
		 */
		validateSubscribeForm : function(form) {
			var email = form.email.value || "";
			var firstName = form.firstName.value || "";
			var lastName = form.lastName.value || "";
			
			var errors = [];
						
			if (!firstName.length) {
				errors.push("First name is required.");
			}
			if (!lastName.length) {
				errors.push("Last name is required.");
			}
			if (!email.length || !isValidEmail(email)) {
				errors.push("Valid email address is required.");
			}
			
			
			if (!errors.length) {
				return true;
			};
			
			var errorMessage = "Newsletter subscription form could not be submitted due of the following errors:";
			errorMessage += "\n\n - " + errors.join("\n - ");
			
			alert(errorMessage);
			
			return false;			
		},
		
		/**
		 * @method validateUnsubscribeForm - Validates the unsubscribe form has a valid email address entered.
		 * @param {Form} form - The form DOM element to look in for email address field.
		 * @return {Boolean} true if form is valid.
		 * @author gregs 2009-09-22
		 */
		validateUnsubscribeForm : function(form) {
			var email = form.emailUnsubscribe.value || "";
			
			if (!isValidEmail(email)) {
				alert("Please enter a valid email address in order to unsubscribe.");
				return false;				
			};
			
			return true;
		}		
	};
};