You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I planned to meet my client in DFW, can you please help me to book a flight ticket from OAK?

ASSISTANT: Sure, we are here to help you. May I know your trip dates?

USER: I prefer to travel on Apr 18 and Apr 20.

ASSISTANT: Do you need any break in your journey?

USER: I prefer to travel in a connecting flight.

ASSISTANT: May I know your depart and arrival time?

USER: I am comfortable at any time.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your good name please?

USER: I am Betty Moore.

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

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.