You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to change my reservation, due to some health problems I am unable to travel those dates, can you please change my reservation?

ASSISTANT: Sure, I will help you. May I know your name please?

USER: Thanks. Sure, my name is Kevin Smith.

ASSISTANT: There is no reservation on your name in our database.

USER: Oh! May be I am not booked my ticket properly at that time.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.