$(document).ready(function (){  
	function submitEmail () {
		var newEmailSubmit = (function() {
			var in_progress = false;
			return function() {
				if($('input').val() && $('input').val().match(/^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/i)) {
					if(!in_progress) {
						in_progress = true;
						$.ajax({
							url: 'signup.php',
							type: 'post',
							dataType: 'json',
							data: $('form').serialize(),
							complete: function(response) {
								if(response.success) {
									$('input').val('');
									alert('Your email address has been added to our mailing list.');
								}
								else{
									alert('Please, input a valid email address.');
								}
									in_progress = false;
							}
						});
					}
				}
				else {
					alert('Please, input a valid email address.');
				}
				return false;
			};
		})(); 	

		newEmailSubmit();
	}
	$('form').submit( function() {
		submitEmail();			
		return false;
	});
});