You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Paul Wilson.

ASSISTANT: Paul Wilson, how may I aid you?

USER: Please help me to book a flight ticket from OAK to DFW.

ASSISTANT: May I know your itinerary dates?

USER: My journey dates are from Oct, 25 to Oct, 27.

ASSISTANT: Do you have any specifications?

USER: I need to return in the evening and I need a single connecting flight.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available on your route.

USER: Nothing to worry, thanks for your information.

ASSISTANT: Thank you for choosing us.