Stackoverflow: Parallax problem?

by tcloninger

HTML

<div class="item">
    <div class="caption">               
        <h1>Lorem Ipsum</h1>                      
    </div>                        
</div>

CSS

.item{
background:url("http://placekitten.com/300/300");
background-attachment:fixed;
height:1000px;
width:100%;
position:relative;
}

.caption{
position:relative;
margin-top:200px;
}

JavaScript

$(window).scroll(function () { 

   $('.caption').css({
      'top' : -($(this).scrollTop()/-2)+"px"
   }); 

});