You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Andrew Lewis. I want to change my exiting reservation, due to heavy rainfall in Seattle, can you help me?

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for choosing us.