You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation, due to my exams has been postponed.

ASSISTANT: Ok.

USER: Can you help me to change it?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name to check the previous reservation?

USER: Ok, You can check my reservation on the name of Timothy Wright.

ASSISTANT: Please, wait for a while.

USER: Sure.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: That's Ok, thanks for your information.

ASSISTANT: Thank you for reaching us.