You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I am Karen Allen, I need to change my reservation ,can you help me with it?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name to change.

USER: No problem, thank you for your assistance.

ASSISTANT: Thanks for opting us.