You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: David Hill here.

ASSISTANT: How can I help you?

USER: I want to book a flight from Oakland, can you please help me in booking a flight from OAK to DFW?

ASSISTANT: Sure, may I know your journey dates please?

USER: Sure, my travel dates are from 05/18 to 05/20.

ASSISTANT: UA airlines is available in your route with the ticket fare of 100, shall i proceed with the booking?

USER: Ok, please proceed with booking.

ASSISTANT: Your ticket is booked with the flight-1020.

USER: Thank you for your service.

ASSISTANT: Thank you for reaching us.