You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you aid me in booking a flight ticket from LAS to SEA?

ASSISTANT: Sure, help me with the trip dates?

USER: I am planning to start on Apr 27th and return back on Apr 29th.

ASSISTANT: May I know your name please?

USER: I am Lisa Lee.

ASSISTANT: Do you have any preferences?

USER: I prefer to travel in economy class.

ASSISTANT: Sorry, no flights found in your desired routes.

USER: No issues. Thank you for checking.

ASSISTANT: Thank you for opting us.