tsl143

This will help you to apply css as per scroll event

<script>
       jQuery(document).ready( function() {
   var topOfOthDiv = jQuery("#nav-topbar").offset().top;
   jQuery(window).scroll(function() {
       if(jQuery(window).scrollTop() > topOfOthDiv) {
                        jQuery("#nav-topbar").css({
                          "position":"fixed",
                          "width":"50%"});
       }else{
                         jQuery("#nav-topbar").css({
                          "position":"static",
                           "width":"100%"});
      }
   });
});
       </script>