You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what service you need from us?

USER: I want to change my ticket booking, can you help me in changing my ticket booking?

ASSISTANT: Sure, I am happy to help you. Can you please tell me your name?

USER: Thank you, my name is Sarah Hall.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry to inform you Hall, there is no reservation found with your name in our database.

USER: It's alright, thank you for your help.

ASSISTANT: You are welcome. Thank you for reaching us. Have a nice day.

USER: Welcome.