func signupEmail(email: String, pwd: String) {
        let user = PFUser()
        user.password = pwd
        user.email = email
        // other fields can be set just like with PFObject
//        user["phone"] = "415-392-0202"

        user.signUpInBackgroundWithBlock {
            (succeeded: Bool, error: NSError?) -> Void in
            if let error = error {
                let errorString = error.userInfo["error"] as? NSString
                // Show the errorString somewhere and let the user try again.
                print(errorString)
            } else {
                // Hooray! Let them use the app now.
            }
        }
    }