<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<style>
body {
position: relative;
}
#section1 {padding-top:50px;height:500px;color: #fff; background-color: #1E88E5;}
#section2 {padding-top:50px;height:500px;color: #fff; background-color: #673ab7;}
#section3 {padding-top:50px;height:500px;color: #fff; background-color: #ff9800;}
#section41 {padding-top:50px;height:500px;color: #fff; background-color: #00bcd4;}
#section42 {padding-top:50px;height:500px;color: #fff; background-color: #009688;}
</style>
</head>
<body data-spy="scroll" data-target=".navbar" data-offset="50">
<nav class="navbar navbar-inverse navbar-fixed-top">
<div class="container-fluid">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#myNavbar">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">WebSiteName</a>
</div>
