You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me to book a flight ticket form OAK to DEN?

ASSISTANT: Sure, please share your journey dates?

USER: My travelling dates are July 25 to July 27.

ASSISTANT: Do you have any specifications?

USER: I need a single connection of flight.

ASSISTANT: Is there any class preferences?

USER: No.

ASSISTANT: May I know your good name?

USER: Gary Perez here.

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

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.