You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Christine white, can you help me for changing my existing reservation?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no reservation found with your name.

USER: Oh! It's ok, thank you for your services.

ASSISTANT: Thank you for opting us.