title: button to scroll view. jquery
body: <p>i need to create a button which will be scrolling the view of website on smartphone. after click on it the view should be scrolled down, measure how far it should scroll is window height; 
  html:</p>
  
  <pre><code>&lt;div class="sSite"&gt;
   &lt;a class="arrow"&gt;&lt;img/&gt;&lt;/a&gt;
   &lt;ul&gt;
       &lt;li&gt;&lt;img/&gt;&lt;/li&gt;
       &lt;li&gt;&lt;img/&gt;&lt;/li&gt;
       &lt;li&gt;&lt;img/&gt;&lt;/li&gt;
       &lt;li&gt;&lt;img/&gt;&lt;/li&gt;
       &lt;li&gt;&lt;img/&gt;&lt;/li&gt;
       &lt;li&gt;&lt;img/&gt;&lt;/li&gt;
       ....
   &lt;/ul&gt;
  &lt;/div&gt;
  
  .arrow{
    position: fixed;
    display: block;
  }
  </code></pre>
  
  <p>jquery:</p>
  
  <pre><code>var heightW = $( window ).height();
  var licznik = 0;
  $(".arrow").bind("click touchstart", function() {
      $('html, body').animate({
          scrollTop : heightW
      }, 200); });
  </code></pre>
  
  <p>but it doesn't work, why?
  it always scroll up to the second element li</p>