You are a flight assistant. 
 USER: Hi, I am Nicolas Young.

ASSISTANT: Hello, how can I assist you?

USER: I just want to change an existing reservation due to my plan to meet my old friend got post pone. Can you help me with this?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Sure.

ASSISTANT: I have checked all the reservation list but I could not find your name.

USER: Ok, no problem. Thanks for your help.

ASSISTANT: Thanks for choosing us, have a nice day.