You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

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

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: Debra Green here.

ASSISTANT: Please allow me a minute.

USER: Sure.

ASSISTANT: Debra Green, I am really sorry to inform you that there is no booking found on your name.

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

ASSISTANT: Thank you for reaching us. Have a great time.