You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I aid you today?

USER: Can you please help me in booking my flight ticket from DEN to SFO?

ASSISTANT: Sure, can you please provide your journey dates?

USER: My planned travel dates are June 23-25.

ASSISTANT: Are you looking for any preferred connections?

USER: I prefer to fly in connecting flight.

ASSISTANT: Do you have any other specification to be met?

USER: I want to travel in big brand airlines.

ASSISTANT: May I know your name to proceed further?

USER: Myself, Amy Hill.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that route.

USER: Ok, no issues. Thank you for your service.

ASSISTANT: Thank you for availing us.