You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you today?

USER:  I am hear to book a flight ticket for my vacation. Can you help me with it?

ASSISTANT: Sure, I will help you. Can you please provide me your travelling dates?

USER: My planning dates are from 08/23 till 08/25.

ASSISTANT: Ok, may I know your travelling airport codes?

USER: My airport codes are from DEN to OAK.

ASSISTANT: Sorry, there is no flight is found on your route.

USER: It's ok, thank you for your information.

ASSISTANT: May I know your name?

USER: My name is Anthony Allen. Welcome.

ASSISTANT: Thank you.