You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: Can you help me to book a direct flight?

ASSISTANT: Sure, I am here to help you with that. Can I know your planned trip dates?

USER: My travel dates are Dec 19 and Dec 21.

ASSISTANT: Ok, can I know your airport codes?

USER: My airport codes are MSP and CLT.

ASSISTANT: May I know your good name?

USER: I am Laura Collins.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: Sorry to say that, there are no flights available based on your travelling dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for approaching us.