You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Charles Turner.

ASSISTANT: How may I help you out?

USER: Suddenly I want to attend entrepreneurship meeting. Can you please help me in changing the reservation?

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

USER: Thank you.

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

USER: Ok not a big problem, anyhow thank you very much for your service.

ASSISTANT: Thank you for reaching us.