You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation due to postpone of my event. Could you please help me?

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

USER: Sure, I am Mark Scott.

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

USER: Sure, I will wait for response.

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

USER: No worries, thank you for the information.

ASSISTANT: Thanks for reaching us.