我似乎无法使用SWIFT中的UIAlertViewController从UITextField获取输入值？

Using iOS9 and Swift to test this UIAlertViewController. So far I am able to get the popup for the user to enter the text("Email address"). In fact I have the entered text by the user as well. but the the text displays: Optional("[email protected]"). I apologies in advance but I am rookie at the moment. Thank you so much in advance for the hints.Using iOS9 and Swift to test this UIAlertViewCo