You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please book a ticket from OAK to HOU to attend Sports festival?

ASSISTANT: Sure, please share your journey dates?

USER: My travelling dates are Sept 1 and Sept 3.

ASSISTANT: Do you have any specifications?

USER: I want a direct flight.

ASSISTANT: Is there any class preferences?

USER: I prefer economy class.

ASSISTANT: May I know your good name?

USER: Sure, I am Stephen Mitchell.

ASSISTANT: Sorry, no flights found on your given details.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.