Sticky Icky from Komodomedia.js

// http://www.komodomedia.com/wp-content/themes/kmv4/scripts/global.js?new

var Sticky = function( $obj, opts ){
      
   $(window).scroll( 
      function(e){
         Sticky.onScroll(e, $obj, opts );
      });
   
}
Sticky.onScroll = function( e, $o, opts ){
   
   var iScrollTop = $(window).scrollTop();
   var sClass = "sticky";
   
   //set original data
   if( !$o.data(sClass) ){
      $o.data(sClass, {css:{position:$o.css('position'),top:$o.css('top')}, offset:$o.offset()} );
   }
   var oOrig = $o.data(sClass);
   var bIsSticky = $o.hasClass(sClass);
   
   if( iScrollTop > oOrig.offset.top && !bIsSticky ){
      $o.css({position:'fixed',top:0}).addClass(sClass);
   }else if(iScrollTop < oOrig.offset.top && bIsSticky){
      $o.css(oOrig.css).removeClass(sClass);
   }   
   
}
Sticky( $('#ad_block') );