You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am Mark Martinez. Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, please wait a minute.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting, no reservation found on your name in the database.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.