You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Daniel Nelson. I want to book a flight ticket from LAS to PHX, can you please help me?

ASSISTANT: May I know your travelling please?

USER: Sure, my trip dates are Mar 18 and Mar 20.

ASSISTANT: Do you need any specifications?

USER: My departing time is evening.

ASSISTANT: Please wait a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there are no flight tickets available on your journey dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching our service.