You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Anna Robinson. I want to to travel to Charlotte this weekend, could you help me in booking the ticket?

ASSISTANT: Sure, may I know the airport codes?

USER: It's from PHX to CLT. The dates of travel are from 08/20 to 08/22.

ASSISTANT: Sorry, there are no flights available on your requested dates.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you, have a nice day.