Can't show full browser height

My code doesn't show full browser height with jQuery link code - https://goo.gl/RG60n1

here is my html -

      <div class="container contentContainer">

            <div class="row">

            <div class="col-md-6 col-md-offset-3" id="topRow">

                <h1>Get Work. Done</h1>

            </div>
        </div>
     </div> 

      

        
        
        
      

    

here css -

  .contentContainer
        {
            background-image:url('laptop1.jpg');
            height:400px;
            width:100%;
            background-size:cover;
        }

      

        
        
        
      

    

And jquery -

    <script>

        $(".contentContainer").css("height",$(window).height());

   </script>

      

        
        
        
      

    

I am using jQuery version 1.11.2 min.