You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to visit Washington-DC, can you please help me to book my flight ticket from DFW to DCA?

ASSISTANT: May I know your trip dates?

USER: I want to depart on Sept 21st and return back on Sept 23rd.

ASSISTANT: Do you prefer any specifications?

USER: Yes, I need a flight having single connection.

ASSISTANT: May I know your name?

USER: My name is Jessica Perez.

ASSISTANT: Sorry to inform you that unfortunately there is no flights available by the given details.

USER: Not an issue. Thank you for the information.

ASSISTANT: That's ok, thank you.