You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you at present?

USER: Christine Harris here, due to sudden work  I need to change my reservation. Can you please help me with it?

ASSISTANT: Ok, I can help you. Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, we did not find any reservation on your name.

USER: Ok,not an issue. Thank you for your information.

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