You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Karen Davis. I want to change my dates in existing reservation. Can you aid me in changing my reservation?

ASSISTANT: Sure, give me a minute.

USER: Take your time.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: No issues. Thank you for checking.

ASSISTANT: Thank you for opting us.