You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I support you?

USER: Could you please change my existing reservation due to postpone of my trip?

ASSISTANT: Sure, I am perky to help you. Can you please let me know your good name?

USER: My name is Kenneth Johnson.

ASSISTANT: Sorry, we did not find any active reservation on your name in our data.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for choosing us.