You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I assist you today?

USER: Need a flight ticket with the name Dennis Harris.

ASSISTANT: Sure, can you please provide me with your journey details?

USER: My travelling dates are from May 31st to June 2nd. I want to travel from Denver, CO- DEN to San Francisco, CS- SFO.

ASSISTANT: OK, give me a moment I will check the availability and revert you.

USER: OK, sure.

ASSISTANT: Thank you for waiting, I am sorry to say we did not find any flight with your requirements.

USER: OK, that's fine. Thank you.

ASSISTANT: Have a nice day.