$('.desiderio').mouseover( function () {
var currentId = $(this).attr('id');
var pos = $(this).offset();
var largh = $(this).width();
var ptop = pos.top;
var pleft = pos.left;
ptop = ptop;
$('#' + currentId + '> .add').css({top: ptop, "left": (pleft + largh) });
$('#' + currentId + '> .add').show();
});