You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you now?

USER: I need your assistance about modification of my reservation which I have done long back to travel in the next month to Chicago but all of sudden my schedule got postponed to some other as on of my relative got expired last night. Can you please help me about that?

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you for your positive response.

ASSISTANT: Can I have your name please?

USER: Sure, my name is Timothy Thompson.

ASSISTANT: Ok, please wait a moment.

USER: Sure, I will wait.

ASSISTANT: Sorry Robert Perez, no reservation has found under your name to change.

USER: Not a big deal, anyways thank you for the information.

ASSISTANT: Thank you for choosing us, have a good day.