How to overlay div / box on mouseover?

Question

I have a link and when user hover mouse over it, it should display a box (div) under the link. The box should overlay whatever is under it. How can I do it using css or javascri

Answer 1

$("#id").mouseover(function(){
   $("a[rel='#petrol']").overlay().load();
});
$("#id").mouseout(function(){
   $("a[rel='#petrol']").overlay().close();
});