You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I want to spend some more days with my friend, I want to change my existing reservation. Please help me out.

ASSISTANT: May I know your name?

USER: My name is Jerry Young.

ASSISTANT: Please hold on for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation is found by your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for contacting us.