You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

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

ASSISTANT: Sure, may I know your name?

USER: Thank you. Please check my reservation with my name Rebecca Gonzalez.

ASSISTANT: Please wait a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, there are no active reservations to change your trip.

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

ASSISTANT: Thank you for reaching our service.

USER: Most welcome.