You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am William Carter.

ASSISTANT: How can I assist you today?

USER: My live concert event is changed to other place. So, please help me with change in existing reservation.

ASSISTANT: Sure, wait for a while I will check and revert you back.

USER: Sure.

ASSISTANT: Thanks for your time. There is no reservation found with your name.

USER: Thanks for your assistance.

ASSISTANT: Thank you for reaching us.