HTML experts here? map questio

Help~ I am using HTML on Unix. i have an image of map of china, and the map is divided into provinces. now i want the user able to click on each province, and a new website is poped up showing the information related to that specific province.
I know I can use


...


My question is how to decide x1,y1 these coordinates once you attached the map on screen...


Xie Xie la~~~