title: Jquery typing effect on scroll bug
body: <p>Hi I have some js code that do typing effect on my web page it start typing when you scroll down end of page. For first it work normally  but when you start scroll faster down to up the typing effect goes crazy how can I fix that</p>
  
  <p><a href="http://conceptmds.com/demo/work" rel="nofollow">demo page</a></p>
  
  <p>code </p>
  
  <pre><code>$(window).scroll(function (e) {
      var elem = $(".hello-page");
      var scrollTop = $(window).scrollTop();
      var blockTop = elem.offset().top;
      var docHeight = $(document).height();
      var windowH = $(window).height();
  
      if (scrollTop &gt;= blockTop) {
          var helloPageA = $(".hello-page").find("a");
          var text = helloPageA.attr("data-text");
          helloPageA.text('');
          $.each(text.split(''), function (i, letter) {
              setTimeout(function () {
                  helloPageA.html(helloPageA.html() + letter);
              }, 150 * i);
          });
      } else {
          elem.find("a").text('');
      }
  });
  </code></pre>
  
  <p><a href="http://jsfiddle.net/xezs6h0x/" rel="nofollow">jsfiddle example</a></p>
  
  <p>Thanks for your help</p>