// By Nick Rigby - Checks for a valid sign-up email address
// Regular expression from http://www.quirksmode.org/js/mailcheck.html

function CheckEmail() {
	
	var signupButton = document.getElementById("signup-button");
	
	signupButton.onclick = function() {
	
		var email = document.getElementById("email").value;
		var emailFilter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
		
		if (emailFilter.test(email)) return true;
		else {
			alert("Please enter a valid email address");
			return false;
		}
		
	}
	
}

Event.observe(window, "load", CheckEmail, false);