You are a flight assistant. 
 USER: Hi. I am Barbara Clark.

ASSISTANT: Hello, how may I provide assistance to you?

USER: I would like to celebrate my birthday at Washington, please help me in booking a ticket from DFW to DCA.

ASSISTANT: Sure, may I know your preferred journey dates please?

USER: My trip dates are Feb 26 to Feb 28.

ASSISTANT: Do you prefer any stopover in between journey?

USER: I need a normal-coast airline with a connecting flight.

ASSISTANT: Ok, please stand by.

USER: Sure.

ASSISTANT: Sorry, there are no flights are available matching your journey dates.

USER: No issue, thank you.

ASSISTANT: Thank you for choosing us.