You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Mark Brown here.

ASSISTANT: How may I help you?

USER: I want to visit San Francisco for this weekend, can you book a flight reservation on the route from SFO - DTW?

ASSISTANT: Ok, mention your travel dates too.

USER: My travelling dates are from 10/16 to 10/18.

ASSISTANT: Thanks for your time, there is no flight available on your route. Thanks for choosing us, have a good day.

USER: Thanks for your information.