You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Charles Anderson. Can you help me in booking the ticket from LAS to PHX?

ASSISTANT: Sure, please mention your travelling dates.

USER: My planning dates are from 12/15 to 12/17. I need a direct flight, please make sure about that.

ASSISTANT: Please wait for a moment, while I search for the flight.

USER: Ok.

ASSISTANT: Thanks for your patience, there is no flight for you with your preferences.

USER: That's fine. Anyway, thank you.

ASSISTANT: Thanks for reaching us.