You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My friends planned for the get together, but some of my friends are unable to come because they have final examinations, so I would like to change my existing reservation. Will you check my reservation and modify the ticket please?

ASSISTANT: Sure, let me check our database. May I know your name to change your reservation?

USER: My previous reservation is confirmed with the name Larry Wilson. So please check with this name.

ASSISTANT: Sure, please hold on for a while.

USER: Ok, I will wait, take your time.

ASSISTANT: Sorry Larry, we could not find a reservation by your name.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.