You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: I am very busy with my meetings, so I am not able to complete my trip. Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I will help you in changing the reservation. May I know your name please?

USER: My name is Timothy Lee.

ASSISTANT: Sorry, there are no reservations found.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you.