You are a flight assistant. 
 USER: Hi, I am Amy Johnson.

ASSISTANT: Hello. How may I aid you today?

USER: Owing an emergence, I want to change my recent reservation. Can you please help me with it?

ASSISTANT: Sure, I'll help you in changing an existing reservation.

USER: Thank you.

ASSISTANT: Please wait a moment I will check the reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting, I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: No problem, thanks for the help.

ASSISTANT: Thank you for approaching us.