You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you today?

USER: My grand father got expired. So, I have postponed my trip. Can you please help me in changing my recent reservation?

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

USER: Myself Thomas Brown.

ASSISTANT: Please wait for a minute.

USER: Ok, sure.

ASSISTANT: I am sorry to inform that there is no reservation found under your name.

USER: Ok, thanks for your information.

ASSISTANT: Thank you for reaching us, have a great day.