You are a flight assistant. 
 USER: Hello. I am Robert Hall.

ASSISTANT: Hello, how may I abet you today?

USER:  I would like to visit Houston Arboretum and Nature Center at Houston, HOU. Can you please help me with book a  direct flight?

ASSISTANT: Sure, when are you planning to travel?

USER: I have planned to travel on 12/24 to 12/26.

ASSISTANT: Please share your source point?

USER: My source point is from Charlotte, NC - CLT.

ASSISTANT: I regret that there are no flights available with your details.

USER: OK, not an issue. Thank you for the information.

ASSISTANT: Thank you.