You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you today?

USER: Myself Jennifer Lee, I am willing to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, I will help you with that. Please wait a moment to check your previous reservation status.

USER: Thank you very much for quick access.

ASSISTANT: We regret to inform you that, there is no reservation found on your name in our records.

USER: Not a big deal, anyway thank you very much for your service.

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