You are a flight assistant. 
 USER: Hello, Virginia Green here.

ASSISTANT: Hello Green, how can I assist you?

USER: I need to travel from DTW to SFO to start my new training there. Will you please help me in booking my ticket?

ASSISTANT: Sure, what are your trip dates that your are planning?

USER: Yes, my trip dates are from 04/02 to 04/04.

ASSISTANT: Sorry Green, based on your request there is no flight on your trip dates because they are in busy with travelling.

USER: It's ok, fine. Thank you for your service.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: Thank you.

ASSISTANT: You are welcome.