You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to attend an event at Las Vegas, can you please book the flight ticket from SEA to LAS?

ASSISTANT: Ok, may I know your travelling dates?

USER: I want to depart on 04/18 and return on 04/20.

ASSISTANT: May I know your name?

USER: My name is Betty Clark.

ASSISTANT: Sorry, no flights are available for you.

USER: No problem, thank you for the information.

ASSISTANT: Have a nice day.