You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I'm James Lee.

ASSISTANT: What type of help that you need from us?

USER: Due to heavy work load in my office, I want to postpone my trip. Please help me in changing my existing reservation.

ASSISTANT: Yes, I can help you. Please give me a moment.

USER: Sure.

ASSISTANT: Thank you for waiting. I could not found any previous reservation on your name to modify your booking.

USER: That's ok, may be I have done a wrong booking. Thank you anyways.

ASSISTANT: It's my pleasure.