You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Can you help me to change the reservation which I have done recently?

ASSISTANT: Sure, we are here to help you. May I know your name please?

USER: Ok, thank you for the positive response. My name is Paul Lewis.

ASSISTANT: Sorry, we could not find any reservation on your name.

USER: That is ok. Thank you for providing the information.

ASSISTANT: Thank you for choosing us.