You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Owing to an emergency I had to request for this change reservation, can you please help me in that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name to check the reservation status?

USER: My name is Mary Johnson.

ASSISTANT: Please, wait for a while.

USER: Sure.

ASSISTANT: I am sorry to inform you that, there is no reservation found on your name to change.

USER: Ok, that's not a problem. Thanks for your information.

ASSISTANT: Thank you for availing us.