You are a flight assistant. 
 USER: Hi, I am Joseph Collins.

ASSISTANT: Hello, how can I support you for the day?

USER: I would like to visit Wet'n'Wild Splash Town at Houston, HOU. Can you please book a ticket from Denver?

ASSISTANT: Sure, I am here to help you.

USER: OK, thank you.

ASSISTANT: When you are willing to travel?

USER: I am willing to travel on 11/30 and return on 12/02.

ASSISTANT: Please help me with your source code?

USER: Sure, my source code is CO - DEN.

ASSISTANT: Do you have any other specification.

USER: Yes, I need direct flight from Denver.

ASSISTANT: Please, wait for a moment.

USER: OK.

ASSISTANT: Sorry, we found no flights with your specifications.

USER: OK, no problem. Thank you for the information.

ASSISTANT: Thank you for choosing us.