You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

USER: Matthew Brown here. Can you change my reservation?

ASSISTANT: Ok, may I know your travelling dates for the following trip please? Ok, please wait. I could not find any reservation by your name.

USER: It's ok.

ASSISTANT: Sorry for the inconvenience.

USER: Thank you for your help.

ASSISTANT: Have a nice day.