You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Melissa Perez.

ASSISTANT: How may I help you out?

USER: I need to change my reservation due to my planned event got postponed. So please help me with that.

ASSISTANT: Sure, I will help you in changing the reservation.

USER: Thank you for accepting my request.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: Oh! It may not be booked properly due to server issue. Anyway, thank you for your time.

ASSISTANT: Thank you for choosing us.