You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I have to change my travelling dates in my previous reservation due to my planned event got postponed. So please help me with that.

ASSISTANT: May I know your name please?

USER: Ok, my name is Brenda Green.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you for opting us.