You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you for today?

USER: I want to change my reservation, can you help me?

ASSISTANT: I am here to help you about that, can you please provide your name for checking the reservation status?

USER: I am Sandra Jones.

ASSISTANT: Please wait for a while to check it.

USER: Sure.

ASSISTANT: Sorry Sandra Jones, there is no active reservation under your name to change the reservation.

USER: No problem, thanks for checking.

ASSISTANT: You are welcome, thank you for reaching us.