You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I have your name please?

USER: Sure, I am Robert Harris from Seattle.

ASSISTANT: May I know what kind of service are you expecting from us?

USER: Actually, I made a reservation earlier to undergo a small surgery this month to remove the stones in my Kidney but my appointment got changed to some other dates. Will you help me in changing my reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a minute to check the status of your reservation.

USER: Sure.

ASSISTANT: Thanks for your patience, we are sorry to say that no active reservation was found on your name.

USER: No problem, thanks for your prompt response.

ASSISTANT: Thank you for approaching us.