title: Jquery scroll plugin scrolls down only
body: <p>Im making a plugin with jquery and it makes use of a mouse scroll event. 
  The problem is i get it scrolls down even when im scrolling up.</p>
  
  <p>Here i got my code</p>
  
  <p>HTML:</p>
  
  <pre><code>     &lt;body&gt;
          &lt;!-- &lt;div id="element"&gt;&lt;/div&gt; --&gt;
          &lt;div id='wrapper'&gt;
              &lt;img id='img1' src='./images/image1.jpg'&gt;
          &lt;/div&gt;
  
          &lt;script&gt;
              $(document).ready(function()
              {
                  $(document).scrollPage();
              });
          &lt;/script&gt;
      &lt;/body&gt;
  </code></pre>
  
  <p>Javascript:</p>
  
  <pre><code>$.extend(Plugin.prototype, {
          init: function () {
              document.addEventListener('scroll', this.checkScroll);
          },
          checkScroll: function(event) {
              //Guess the delta.
              var delta = 0;
  
              if (event.wheelDelta) {
                  delta = event.wheelDelta/120;
              }
              else if (event.detail) {
                  delta = -event.detail/3;
              }
  
              if(delta / 120 &gt; 0){
                  console.log('up');
              }
              else{
                  console.log('down');
              }
          }
      });
  </code></pre>
  
  <p>Somehow when i scroll the code always come in the else statement console.log('down');</p>
  
  <p>is the formula delta / 120 > 0 wrong in this code? </p>