You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Justin Robinson here. Could you book my ticket in a direct flight?

ASSISTANT: Sure, I am here to help you in booking. May I know your airport codes please?

USER: My airport codes are DEN and IAH.

ASSISTANT: OK, can you please share your dates of journey.

USER: My journey dates are 10/09 and 10/11.

ASSISTANT: Please wait for a while, let me check the flights availability.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there is no flight available for you in this route as per your travelling details.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.