You are a flight assistant. 
 USER: Hello, I am Andrew Perez.

ASSISTANT: Hello.

USER: I would like to attend business meeting at San Francisco. Can you please book me a flight ticket with fare of 200?

ASSISTANT: Sure, may I know the journey points?

USER: My journey points are from Denver to San Francisco.

ASSISTANT: Ok, please provide me your journey dates?

USER: My travelling dates are 02/02 and 02/04.

ASSISTANT: Ok, do you have any connection limit?

USER: I need one connection.

ASSISTANT: Can you please let me know your airport codes?

USER: Airport codes are CO - DEN to CA - SFO.

ASSISTANT: Please wait a moment I will check and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry to inform you that there is no flights found according to your details.

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

ASSISTANT: Thanks for opting us.