You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me with that change my existing reservation?

ASSISTANT: Sure, may I know your name?

USER: My name is Karen Green.

ASSISTANT: Please wait for a moment to check your details.

USER: Sure.

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

USER: No issues, thank you for the checking.

ASSISTANT: Thank you for your time.