You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: Can you help me in booking a flight ticket from OAK to DEN?

ASSISTANT: Sure, May I know the travelling dates?

USER: I want to travel on 01/19, and return on 01/21.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any airline preference?

USER: I prefer for normal cost airline.

ASSISTANT: May I know your name?

USER: I am Debra Edwards.

ASSISTANT: Please wait a minute. Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for opting us.