You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello.

USER: I'm Carolyn Phillips.

ASSISTANT: How may I assist you today?

USER: Please book a ticket from Washington DC-IAD to Washington DC-DCA.

ASSISTANT: Sure, please let me know your planning travelling dates.

USER: Departure is on 09/10 and 09/12 is return date.

ASSISTANT: Is there any connection preference?

USER: Connections limit is 1.

ASSISTANT: Thanks for sharing your journey details, sorry to inform you that there no flights found with your details.

USER: Thanks for the help.

ASSISTANT: Thanks for picking us.