You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Matthew Walker here, can you please book a ticket from DCA to MSP? As I'm planning to visit Minneapolis.

ASSISTANT: Sure, can you please share your travel dates?

USER: Sure, my planned departure date is 29th February and I want to return back by 2nd March.

ASSISTANT: Do you have any class preference?

USER: No but my departure time should be afternoon.

ASSISTANT: I am sorry to inform you that there is no flight available during afternoon time.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: You are welcome. Thank you for contacting us.