You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: Please help me out in changing my recent reservation.

ASSISTANT: Sure, may I know your name?

USER: Charles Roberts is my name.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Sorry Charles Roberts, no reservation is available by your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.