You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Daniel Rodriguez.

ASSISTANT: How can I assist you today?

USER: I would like to book a ticket to Oakland, can you help me?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: My travel dates are 12/13 and 12/15.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Please provide your airport codes.

USER: My airport codes are from LAS to OAK.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: I have an important meeting in Oakland and you are saying there are no flights.

ASSISTANT: I regret to inform you that there are no flights to book a seat for your journey due to sold out of tickets.

USER: You should provide some extra flights when heavy bookings are present.

ASSISTANT: As per customers demand we are providing flights, but all tickets are sold out. we add more flights next time on this route, please excuse us at this time.

USER: Ok, I will try for another alternative way to complete my trip. Thank you for your information.

ASSISTANT: Thank you for reaching us.