fix a navbar to top of page js

/* The navigation bar */.navbar {  overflow: hidden;  
  background-color: #333;  position: fixed; /* Set 
  the navbar to fixed position */  top: 0; 
/* Position the navbar at the top of the page */  width: 
100%; /* Full width */}/* Links inside the navbar */
  .navbar a {  float: left;  display: 
  block;  color: #f2f2f2;  text-align: 
  center;  padding: 14px 16px;  
  text-decoration: none;}/* Change background on mouse-over */.navbar 
  a:hover {  background: #ddd;  color: 
  black;}/* Main 
content */.main {  margin-top: 30px; /* Add a top 
  margin to avoid content overlay */}