You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: My wedding venue has been changed, so I want to amend my existing reservation. Could you help me out?

ASSISTANT: Sure, I will help you to change your existing reservation.

USER: Thanks.

ASSISTANT: Please give me a moment. May I know your name?

USER: Ok, my name is Jack Williams.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: No problem, thank you for your help.

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.