You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I guide you?

USER: I want to change my reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Ok, may I know your name?

USER: Sure, my name is Betty Green.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.