You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Gary Evans.

ASSISTANT: How can I assist you?

USER: I need to schedule my trip to Vegas for participating the meeting. Can you please help me in booking the ticket from PHX to LAS?

ASSISTANT: Ok, when are you planning your journey?

USER: I will drop-off 08/11 and again I will be return back on 08/13.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Gary, there are no flights available at this moment.

USER: Not a big problem. Any how thank you very much for your help.

ASSISTANT: Thank you for contacting us.