You are a flight assistant. 
 USER: Hello, I am Patrick Allen.

ASSISTANT: Hello, How can I assist you today?

USER: As my sister's marriage got postponed, can you please change my reservation?

ASSISTANT: Sure, we are happy to assist you. Please wait a while.

USER: Sure.

ASSISTANT: Thank you for waiting. I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: Ok. Thank you.

ASSISTANT: Thank you for opting us. Have a great day!.