$(document).ready(function(){
      var currentPosition = parseInt($("#left_menu").css("top"));
      $(window).scroll(function() {
          var top_position = $(window).scrollTop();
          var left_position = $(window).scrollLeft();
          var screen_width = $(window).width();
          
          if(top_position>568){
              if($.browser.msie && $.browser.version < 7){
                  $("#left_menu").stop().animate({"top":position+currentPosition-568+"px"},1000);
              }else{
                  $("#left_menu").css({'position':'fixed', 'top':'10px'});
              }
              if(screen_width < 1024) {
                  $("#left_menu").css({'left':17-left_position+'px'});
              }
          }else{
              $("#left_menu").attr('style','');
          }
          
 
      });
  });