You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I am planning to meet my colleague in Charlotte, so please book a flight ticket from HOU to CLT.

ASSISTANT: Sure, we are here to help you. Can you share me your travelling dates?

USER: I want to fly on Dec 22, return on Dec 24.

ASSISTANT: May I know your name?

USER: My name is Carolyn Smith.

ASSISTANT: Do you have any other specifications?

USER: My depart time should be afternoon.

ASSISTANT: Ok, wait for some time.

USER: Sure, I want direct flight.

ASSISTANT: Thanks for waiting there are no flights found on your details.

USER: No problem, thank you.

ASSISTANT: Thanks for approaching us.