You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How can I assist you?

USER: I am  Samuel Jackson. I would like to visit Oasis Water Park in Phoenix, PHX. Can you please book a flight ticket from LAS?

ASSISTANT: Sure, Please help me with your travel dates.

USER: My journey dates are, start on 12/20 and return back on 12/22.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.