You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you today?

USER: I want to change my existing reservation, can you help me with that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: My name is Christine Walker.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation found on your name.

USER: No issues, thank you for the checking.

ASSISTANT: Thank you for availing us.