You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I would like to change my reservation due to sudden postponement of trip, can you please help me out with that?

ASSISTANT: Sure, I will aid you with that. Can you please mention your name for further process?

USER: Thank you for accepting my request, I have reserved it on the name of Brian Phillips.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: There is no previous reservation available under your name.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.