You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to book a flight ticket to SEA from LAS, can you please help me out?

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Please let me know your journey dates?

USER: Sure, my planned travelling dates are May 04 and May 06.

ASSISTANT: Is there any other requirement?

USER: Yes, I refer direct flight.

ASSISTANT: May I know your name?

USER: Sure, my name is William Lewis.

ASSISTANT: Ok. Sorry currently there are no flights for your travelling dates.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you.