Bootstrap导航中的表单

<nav class = "navbar navbar-default" role = "navigation">

   <div class = "navbar-header">
      <a class = "navbar-brand" href = "#">yiibai</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">Submit</button>

      </form>    
   </div>

</nav>