Technique # 1.html

<!doctype html>
<html lang="en">
  <head>
    <!-- Required meta tags -->
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

    <link rel="stylesheet" type="text/css" href="Technique # 1.css">
    <link rel="stylesheet" type="text/css" href="css/bootstrap.min.css">
    <title>SDVANCED BOOTSTRAP TECHNIQUES</title>
</head>
<body>


<div class="container">
<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown button
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
  </div>
</div>
</div>













<script type="text/javascript" src="jd/bootstrap.min.js"></script>

<script>$('.dropdown-toggle').click(function(e) {
		  if ($(document).width() > 768) {
		    e.preventDefault();

		    var url = $(this).attr('href');

		    if (url !== '#') {
		      window.location.href = url;
		    }

		  }
		});
</script>
</html>
</body>