Clickable geographic maps

I need a clickable world map designed. This will be a drill down map, so that at the top level we have a map of the world showing only continents. The continents will be clickable and when you click on each continent you, a new image is displayed with the continent and the individual contries in each. The countries again will be clickable and when you click each one, a new map of that country is displayed with the regions in the country. These regions need to be clickable as well. The click events must be accessible, so i can do other things I want. The hover event must also be accessible. An example is : [login to view URL] As you hover over each clickable area, the colour of that area should change. Professional looking colours have to be used.