bootstrap call

https://code.jquery.com/jquery-3.2.1.slim.min.js
https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js
https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js


    <script src="assets/js/jquery-1.12.4.min.js"></script>
    <script src="assets/js/popper.min.js"></script>
    <script src="assets/js/bootstrap.min.js"></script>