bootstrap

<div class="navbar navbar-inverse navbar-fixed-top" role="navigation">
      <div class="container">
        <div class="navbar-header">
          <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
          </button>
          <a class="navbar-brand" href="#">Project name</a>
        </div>
        <div class="navbar-collapse collapse">
          <form class="navbar-form navbar-right" role="form">
            <div class="form-group">
              <input type="text" placeholder="Email" class="form-control">
            </div>
            <div class="form-group">
              <input type="password" placeholder="Password" class="form-control">
            </div>
            <button type="submit" class="btn btn-success">Sign in</button>
          </form>
        </div><!--/.navbar-collapse -->
      </div>
    </div>

<nav class="navbar navbar-default" role="navigation">
   <div class="navbar-header">
      <a class="navbar-brand" href="#">W3Cschool</a>
   </div>
   <div>
      <form class="navbar-form navbar-left" role="search">
         <div class="form-group">
            <input type="text" class="form-control" placeholder="Search">
         </div>
         <button type="submit" class="btn btn-default">提交</button>
      </form>    
   </div>
</nav>

<nav class="navbar navbar-default" role="navigation">
   <div class="navbar-header">
      <a class="navbar-brand" href="#">W3Cschool</a>
   </div>
   <div>
      <ul class="nav navbar-nav">
         <li class="active"><a href="#">iOS</a></li>
         <li><a href="#">SVN</a></li>
         <li class="dropdown">
            <a href="#" class="dropdown-toggle" data-toggle="dropdown">
               Java 
               <b class="caret"></b>
            </a>
            <ul class="dropdown-menu">
               <li><a href="#">jmeter</a></li>
               <li><a href="#">EJB</a></li>
               <li><a href="#">Jasper Report</a></li>
               <li class="divider"></li>
               <li><a href="#">分离的链接</a></li>
               <li class="divider"></li>
               <li><a href="#">另一个分离的链接</a></li>
            </ul>
         </li>
      </ul>
   </div>
</nav>