You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, may I know your name for checking previous reservation in our database?

USER: I am Catherine Adams.

ASSISTANT: Please wait for a moment.

USER: OK.

ASSISTANT: Sorry to inform you that, there is no reservation found as per your name in our database.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us with a query.