You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Christopher Lewis. I want to book a flight ticket.

ASSISTANT: OK. Can you give me your journey dates?

USER: My travelling dates are from 08/20 to 08/22. My airport codes are from MN-MSP to NC- CLT.

ASSISTANT: OK,just hold on.

USER: OK.

ASSISTANT: I am really sorry because there is no flight available based on your details.

USER: OK. Thank you for your information.

ASSISTANT: Have a nice day.