<nav class="navbar navbar-inverse navbar-static-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>
    <div>
      <div class="collapse navbar-collapse" id="myNavbar">
        <ul class="nav navbar-nav">
          <li><a href="#section1">Section 1</a></li>
          <li><a href="#section2">Section 2</a></li>
          <li><a href="#section3">Section 3</a></li>
          <li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" href="#">Section 4 <span class="caret"></span></a>
            <ul class="dropdown-menu">
              <li><a href="#section41">Section 4-1</a></li>
              <li><a href="#section42">Section 4-2</a></li>
            </ul>
          </li>
        </ul>
      </div>
    </div>
  </div>
</nav>