You can use jQuery to achieve this
Example:
$(function () {
$('.map').maphilight();
});
Go through this LINK to know more.
If the above one doesnt work then go through this link.
EDIT :
Give same class to each area tag like class="mapping"
and try this below code
$('.mapping').mouseover(function() {
alert($(this).attr('id'));
}).mouseout(function(){
alert('Mouseout....');
});