You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Can you please book a ticket from DEN to MSP to meet my sister?

ASSISTANT: Sure, I will help you with that. Can you please share your preferable journey dates?

USER: My travelling dates are Nov 25 and Nov 27.

ASSISTANT: May I know your name please?

USER: I am John Carter.

ASSISTANT: Do you have any specifications?

USER: My depart time is afternoon.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no flight found under your details.

USER: Ok, Thank you.

ASSISTANT: Thank you.