You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: I need to book a ticket from LAS to DFW. Could you book a ticket?

ASSISTANT: Sure, may I know your travelling dates?

USER: Departure is on July, 10 and return date is July, 12.

ASSISTANT: Do you need any specifications?

USER: I would prefer direct flight.

ASSISTANT: On which name shall I reserve flight ticket?

USER: My name is Brandon White.

ASSISTANT:  Please wait.

USER: Sure.

ASSISTANT: Sorry, there are no flights found on given dates.

USER: Thank you.