You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Dorothy Baker. Can you please book a flight ticket from DEN to LAX?

ASSISTANT: May I know your desired travel dates please?

USER: Sure, I need to travel on dates of 03/23 and 03/25.

ASSISTANT: There is no flight available on your desired travel dates.

USER: Ok, no problem. Anyway, thank you for your time.

ASSISTANT: Thank you for reaching us.