You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Alexander Lewis. I would like to book a ticket from DCA to MSP, can you please help me out?

ASSISTANT: Let me know your travel dates.

USER: I am travelling on these dates Oct 6th and 8th.

ASSISTANT: Do you have any preference?

USER: I prefer return in the afternoon.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you.