You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am planning to attend a Tennis competition in Oakland OAK from DEN. Can you find a flight ticket for me?

ASSISTANT: Sure, may I know your planned journey dates?

USER: Sure, I am planning to travel on these days that is on Sept 09 and return on Sept 11.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a single connecting flight.

ASSISTANT: Can I know your airline preference?

USER: No, I don't have any other preference.

ASSISTANT: Please provide your name for further process.

USER: Yes, I am Stephanie Carter.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your preferred dates.

USER: Ok, not an problem. Thank you for your help.

ASSISTANT: Thank you for opting us.