You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Edward Collins. I am a professor and I have to submit the report in main university which is in San Francisco, can you help me in flight ticket booking on 04/14?

ASSISTANT: Sure, I am glad to help you in booking.

USER: Thank you for accepting my request.

ASSISTANT: May I know your planned source airport code?

USER: Sure, my source region airport code is CO-DEN.

ASSISTANT: Please provide the recur date if you are planned.

USER: Yes, I have planned to return back after two days on 04/16 and please book the return ticket also.

ASSISTANT: May I know your destination airport code?

USER: Sure, my destination region airport code is CA-SFO.

ASSISTANT: Please wait for a while to check for the flight availability.

USER: Sure, I don't mind for waiting and please go ahead with your search and provide me an enhanced flight for my journey.

ASSISTANT: Thank you for waiting. Here, there are no flights available for your desired intent. Sorry for the inconvenience caused.

USER: Ok, not a problem. Thank you for your information.

ASSISTANT: Thank you for opting us.