You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: I want to change my reservation due to emergency work in office, can you help me?

ASSISTANT: Sure, I will help you. Could you please provide your name to check your previous reservation status?

USER: I am Christopher Turner.

ASSISTANT: Ok Turner, please hold on to check.

USER: Ok.

ASSISTANT: We regret that, there is no reservation found with your name in our records.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for approaching us, have a great day.