Datatable pagination - index of the page the user clicked on

pacionet

I am using DataTable pagination and i need to modify the behaviour when clicking on a page number.
How can I get the number of the page the user clicked on?
the fnPagingInfo seems to have only the current page number and not

$('.table_example').on('page', function () {
alert(this.fnPagingInfo().iPage); // CURRENT PAGE
// index of the page the user clicked on ?
});

Thanks
Andrea