// email validator - http://www.w3resource.com/javascript/form/email-validation.php#sthash.YaiMT7Vz.dpuf
function isValidEmail(email)   
{  
	return (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email)); 
}  

// submits the data from the email addresses with error checking
function email_submit() 
{
	var address_selector = "input[name='address']"; 
	var address = $(address_selector).val(); 
	
	// if not a valid email address, show error messages and make red
	if(!isValidEmail(address))
	{
		$("#email-signup-box").addClass("error");
		$("#email-help").html("The email address you provided is invalid.");
		$(address_selector).bind("keydown", function ()
		{
			$("#email-signup-box").removeClass("error");
			$("#email-help").empty(); 
			$(address_selector).unbind("keydown"); 
		}); 
		return; 
	}
	// otherwise submit via ajax
	else
	{
		$("#invalid_address").hide();
		$(address_selector).css('color', 'black'); 
		
		// create data to submit
		var data = {};
		data["address"] = address; 
		
		// ajax
		$.ajax({
			type: 'POST',
			url: 'email/subscribe.php',
			data: data
		}).done (function (link) 
		{
			// if ajax worked correctly, a link starting with http://... is returned
			if (link.substring(0, 4) == "http")
			{
				$("form[name='email']").hide(); 
				$("#email_complete").show(); 

				var msg = "To unsubscribe click <a href='" + link + "'>here</a>"; 
				$("#unsubscribe").html(msg); 
			}
			// otherwise alert the failure
			else
			{
				alert(link); 
			}
		});
	}
}