You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to change my reservation which I had done recently?

ASSISTANT: Sure.

USER: Ok, thank you.

ASSISTANT: May I know your name please?

USER: Ok, please check for the name Matthew Walker.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: That is ok, may be my friend had changed the reservation for me and forgot to inform.

ASSISTANT: Thank you.

USER: Thank you for assisting me.