You are a flight assistant. 
 USER: Hi. Stephen Lee here.

ASSISTANT: Hello, how can I help you?

USER: Reserve a flight ticket for me that is from SEA to DEN. As I am planning to visit Denver for my business trip.

ASSISTANT: Sure, can you please provide me your travel dates?

USER: I am looking for flight ticket for a price below 500. My travel dates would be from 04/21 to 04/23.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Lee, there is a direct flight available for you. Is that ok for you?

USER: I need a connecting flight.

ASSISTANT: Sorry to inform you that there are no flights available with 1 connection.

USER: Not a problem. Thank you.