You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: My name is Jack Perez, I want to change my reservation as my trip to New York is postponed. Can you change my reservation?

ASSISTANT: Sure, I am mirthful to help you with that. Please hold for a moment, let me check your previous reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting. There is no active reservation found with your name in our database to change it.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.