You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Can you please help me in booking a flight ticket from Minneapolis, MSP to Denver, DEN?

ASSISTANT: Sure, can you share your trip dates?

USER: My journey dates are from May 26 to May 28.

ASSISTANT: Do you have any preferences?

USER: My return time is afternoon.

ASSISTANT: May I know your name?

USER: My name is Christopher Nelson.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: Ok, that's not a problem. Thanks for your information.

ASSISTANT: Thank you for opting us.