You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I have done a reservation on my name Betty Lopez, now I want to change it, can you please assist me?

ASSISTANT: Yes, I am happy to help you.

USER: Thank you.

ASSISTANT: Sorry to inform you, there is no ticket booking found under your name in our database.

USER: Ok, no issues with it, thank for your great service done immediately.

ASSISTANT: You are welcome. Thank you for choosing us.

USER: Welcome.