You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Dennis Martin here.

ASSISTANT: Dennis, how may I help you?

USER: Can you please book a flight ticket from DFW to JFK?

ASSISTANT: Please provide your travel dates.

USER: Sure, I need to travel on dates of 09/14 and 09/16.

ASSISTANT: Please give me a moment. Let me check for a best flight for you.

USER: Sure, take your time.

ASSISTANT: Sorry, no flight is available on your route.

USER: It's ok fine, no problem.

ASSISTANT: Thank you for choosing us.

USER: Anyway, thank you for your time.