You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

USER: Christopher Smith here. Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, I am happy to help you with that. Please wait a moment to check your reservation status.

USER: Ok, I will wait.

ASSISTANT: Sorry Christopher Smith, no reservation has found under your name to change.

USER: Anyway, thanks for the information.

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