title: How is scroll height larger than window height?
body: <p>I am trying to make a function stop running before the user scrolls the entire window height, but what I am seeing in the console isn't adding up. Somehow, the scrollHeight (which is the scrollTop value) ends up being more than the window heigh itself. How is this possible?</p>
  
  <pre><code>$(document).ready(function() {
  
      var windowHeight = $(window).height();
  
      if( $(window).width() &gt; 720  &amp;&amp; $(window).scrollTop() &lt; (windowHeight-400) ) {
  
                  $(window).bind('scroll', function(){
  
                  var scrollHeight = $(window).scrollTop();
                  console.log('scroll height', scrollHeight)
                  console.log('window height', windowHeight)
  
                  function parallaxScroll(){
                     $('#main').css('top',(500-(scrollHeight*2))+'px');
                  };
  
                      parallaxScroll();
                  });
      }
  });
  </code></pre>