You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Gregory Brown.

ASSISTANT: Welcome to flight booking agency Brown. How may I help you?

USER: I planned to visit Philadelphia for a music concert, but due to bad weather, the concert is postponed to other dates.

ASSISTANT: Ok, let me check the status of your previous reservation. Actually, there is no reservation on your name to change it.

USER: That's ok. Thank you for your time.

ASSISTANT: Welcome, It's my pleasure.