You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Campbell.

ASSISTANT: How can I aid you at this moment?

USER: I need to book a flight ticket from LAS to SFO, Can you please help me for booking?

ASSISTANT: Sure, I will aid you with that. Could you please mention your preferable travel dates?

USER: I would like to travel on 06/03 to return on 06/05.

ASSISTANT: Is there any additional preferences do you have?

USER: Yes, I need direct flight.

ASSISTANT: Ok, please wait a moment, I will check flight availability in this route.

USER: Sure.

ASSISTANT: Sorry no flights are available in this route as per your requested dates.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.