html5 - Why won't the logo and button be on the same row? -

so i'm trying setup logo on top-left , login button on top right. whenever run in browser, won't stay in same row reason. why that?

<section class="container-fluid">     <div class="row-fluid">         <div class="col-md-6">             <h1>logo here</h1>         </div>         <div class="col-md-6">             <button>login here</button>         </div>     </div> </section>