You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you please book a flight ticket from SFO to DEN?

ASSISTANT: Please provide your trip dates.

USER: My trip dates are May 28 and May 30.

ASSISTANT: Do you need any connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you need any other specifications?

USER: I want a ticket in economy class which should depart in the evening.

ASSISTANT: May I know your name?

USER: My name is Karen Hernandez.

ASSISTANT: There are no flights available on your routes.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for opting us.