You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Can you book a ticket for me?

ASSISTANT: Yes sure, please tell me your airport details.

USER: I want to travel from NV - LAS to DC - IAD.

ASSISTANT: Any preferable dates you want.

USER: The departure is on 03/08 and return is on 03/10.

ASSISTANT: I have a flight tickets on 03/07. You want 1 day before flight.

USER: I want to book the ticket for departure on 03/08.

ASSISTANT: Sorry! I don't have a flight on your preferable day. Can I know your name?

USER: OK, Thank you for the help. Benjamin hernandez.

ASSISTANT: Welcome.