You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I respond to your request?

USER: Please help me in changing my recent reservation.

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Charles Hernandez.

ASSISTANT: Ok, 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: That's ok, thank you for checking.

ASSISTANT: Thanks for reaching us, wish you a happy day.