You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, What kind of help are you expecting from our side?

USER: I would like to change my existing reservation because my trip dates are got postponed, can you help me?

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

USER: I am Jerry Roberts.

ASSISTANT: Thanks for providing your name, Please stay online, I will check the previous list and revert to you.

USER: Sure, take your own time.

ASSISTANT: Thanks for remaining so positive, We are sorry to specify that there is no active reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for your presence. We hope to serve you again.