You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my reservation as I am leaving for business meet, can you please help me out?

ASSISTANT: Sure, I am here to help you with that, can I know your name to proceed further?

USER: Donna Hall here.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us. Thank you for reaching us.