You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is David Clark, can you help me to book a flight ticket from NC - CLT to AZ - PHX?

ASSISTANT: Sure, I will help you to book a flight ticket. Let me know your travelling dates.

USER: Ok, please can I get the flight for the dates I planned which are Nov 25 and Nov 27 respectively.

ASSISTANT: Please give me a moment. Sorry, no flights are available on your route.

USER: Ok, not a problem. Thank you for assisting me.

ASSISTANT: Welcome. Have a nice day. Thank you for choosing us.