You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, please share your good name?

USER: Sure, I am Larry Walker.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your given name.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.