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?

USER: I am Barbara Allen.

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

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you.