You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Please share your trip dates.

USER: Thank you. I have planned my travel dates as Apr 17 and Apr 19.

ASSISTANT: Do you need any connection limit?

USER: I am looking for single connecting flight.

ASSISTANT: Do you need any other specifications?

USER: I would like to depart in evening time so please make sure that.

ASSISTANT: May I know your name?

USER: Sure, myself Cynthia Thompson.

ASSISTANT: There are no flights available on your required dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for choosing us.