You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Green here.

ASSISTANT: How can I aid you?

USER: I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you for considering my request.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry Nancy, there are no reservation found on your name.

USER: Not a big problem, anyway thank you for the information.

ASSISTANT: Thank you for opting us, have a nice day.

USER: Thank you for your help in searching.