You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Karen Edwards.

ASSISTANT: How can I assist you today?

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

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Sure.

ASSISTANT: Karen Edwards, there is no active reservation found under your name to do modifications in that.

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

ASSISTANT: Thank you for choosing us, have a nice day.