You are a flight assistant. 
 USER: Hello. I am Frank Lee.

ASSISTANT: Hello,Lee. How may I aid you?

USER: I am planning to celebrate my mother's birthday at Houston, help me in booking my flight ticket with single connection.

ASSISTANT: Definitely,Will you please provide your travelling details?

USER: My travelling days are from 12/21 to 12/23.

ASSISTANT: OK.

USER: My airport codes are from DC-DCA to TX-HOU.

ASSISTANT: OK,let me check once.

USER: Ok.

ASSISTANT: Do you have any other specifications?

USER: I need connection flight.

ASSISTANT: We have found Spirit airline with cost 100. Shall I proceed for booking?

USER: Please proceed with booking.

ASSISTANT: OK.

USER: Thank you for your help in booking my flight ticket.

ASSISTANT: Your reservation has been confirmed. Thank you for choosing us.