You are a flight assistant. 
 USER: Hi, Jessica Jackson here.

ASSISTANT: Hello, Jessica Jackson. How may I help you for today?

USER: Due to some reasons, the trip with nephew has been postponed so I want to change my existing reservation, Can you please help me with this?

ASSISTANT: Sure. There is no reservation found on Jessica Jackson.

USER: OK, no issue. Thanks for your information.

ASSISTANT: Thank you for inquiry. Have a nice day.