You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my reservation which was done last week due to my bad health. Can you help me?

ASSISTANT: May I know your name?

USER: My name is Paul Walker.

ASSISTANT: We are sorry to inform you that, we did not find any reservation against your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.