You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Charles Perez. Can you please book a flight ticket from DFW to HOU? As I need to go Houston to meet my friend.

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: Thank you. I need to travel on dates of Nov 04 and Nov 06.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: OH! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: You are welcome, have a great day.