You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to alter my ticket details which is booked by my friend, can you please help me in changing the ticket?

ASSISTANT: Sure, I will help you out.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Brian Nelson.

ASSISTANT: Sorry, there are no reservations found.

USER: It's ok, thank you for searching.

ASSISTANT: Thank you for choosing us.

USER: Welcome.