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

ASSISTANT: Hello, how can I guide you for today?

USER: Please book a flight ticket from CLT to IAH.

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I will start on June 24 and return on June, 26.

ASSISTANT: Do you have any class preferences?

USER: No.

ASSISTANT: Do you have any airline preferences?

USER: No.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I need a direct flight and my return time should be at afternoon.

ASSISTANT: Sorry, there are no flights available at your request.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for contacting us, have a nice day.