CODE EXAMPLE FOR JAVASCRIPT

confirm before close modal

//jQuery and Bootstrap Lib's always comes first
$(document).ready(function () { //Dom Ready
    $('.closefirstmodal').click(function () { //Close Button on Form Modal to trigger Warning Modal
        $('#Warning').modal('show').on('show.bs.modal', function () { //Show Warning Modal and use `show` event listener
            $('.confirmclosed').click(function () { //Waring Modal Confirm Close Button
                $('#Warning').modal('hide'); //Hide Warning Modal
                $('#Form').modal('hide'); //Hide Form Modal
            });
        });
    });
});