You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you the day?

USER: I am Barbara Davis. I need to change my existing reservation, can you help me?

ASSISTANT: Sure, I can help you in that.

USER: Thank you.

ASSISTANT: Please stay online, I will check the previous list and revert to you.

USER: Sure.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

USER: Ok, thank you the information.

ASSISTANT: Thanks for approaching with us.