You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: Could you please book a flight ticket from DEN to LAX?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My travelling dates are May 05 and May 07.

ASSISTANT: Can I know your name please?

USER: My name is Donna Baker.

ASSISTANT: Do you need any specifications?

USER: I need a single connecting flight.

ASSISTANT: Can I know your other preferences?

USER: I don't have any other specifications.

ASSISTANT: Sorry, there are no flights found.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.