You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Robert Carter.

ASSISTANT: How can I help you?

USER:  I have to book a flight ticket  that I am unable to do, could you please help me in booking flight ticket on dates 07/26 and 07/28?

ASSISTANT: Sure, please provide your airport codes.

USER: My airport codes are DFW and OAK.

ASSISTANT: Do you have any preferences?

USER: I want to depart at afternoon.

ASSISTANT: Do you have any connection limit?

USER:  I need a connecting flight.

ASSISTANT: Flight-1003 is available in UA airlines with single connection and the flight fare is 100. Can I proceed?

USER: Yes, please.

ASSISTANT: Your booking is confirmed.

USER: Thank you for the help.

ASSISTANT: Thank you for reaching us.