You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Myself Carol Thomas. Will you help me in booking the flight ticket from Dec 19 and Dec 21?

ASSISTANT: Sure, may I know your airport codes please?

USER: My airport code are MSP to DCA?

ASSISTANT: Please wait.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry to inform you that there is no flight available as per your request.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Most welcome.