421288 JavaScript / html task

On page there is big image (map of country). Map separated by imagemap with 7 sections (<area shape=poly>) I need to show layer (div) under each section of image with list of cities when I move mouse over it and hide list when mouse out. Also need to have ability to click on each city. I prefer to use plain javascript/css without JQuery and other "hard" libraries. To make bid - shortly explain how are you going to make this task and show samples of similar tasks.