You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation, can you please help me?

ASSISTANT: Sure, may I know your good name?

USER: Lisa Jackson.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.