You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Helen Phillips.

ASSISTANT: How may I guide you?

USER: Please can you guide me how to alter my previous reservation because suddenly I changed my trip destination.

ASSISTANT: Yes, I can guide you. Please wait for a while, I will check the status of your previous reservation.

USER: Sure, take your time.

ASSISTANT: Sorry, I didn't find any reservation with your name in our records.

USER: It's ok, not a problem.

ASSISTANT: Thank you for approaching us.

USER: You are welcome.