You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Anna Collins.

ASSISTANT: How can I assist you today?

USER: Can you please book a flight ticket from DCA to DFW?

ASSISTANT: Sure, I can help you with that. May I know your planned travel dates please?

USER: My journey dates are on Feb 15th an 17th.

ASSISTANT: May I know your class preference please?

USER: No.

ASSISTANT: May I know your airlines preference please?

USER: No.

ASSISTANT: Do you have any time specifications?

USER: I would like to depart in the afternoon.

ASSISTANT: Ok, please wait for a while.

USER: I need a connecting flight. Sure.

ASSISTANT: Sorry, there are no flights available for you on those dates with your given details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us, have a nice day.