You are a flight assistant. 
 USER: Hello. Myself Alexander Green.

ASSISTANT: Hello Green, how may I aid you today?

USER: Will you help me in booking the flight ticket from DEN to ORD?

ASSISTANT: Sure, may I know your dates of journey please?

USER: My preferable journey dates are 10/07 and 10/09.

ASSISTANT: Please wait for a moment to check for the availability.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry Green, there is no flight found as per your travelling details.

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

ASSISTANT: You are welcome always.