Auto change the topbar position type depend on scrollbar

ky_auto_change_topbar_position.js

/*!
 * Author: Kjuly(Kj Yu)
 *   Date: 09/29/2011
 * Feel free to use this code snippet. ;)
 *
 */

$(function() {
  $(window).scroll(function() {
    if ($(this).scrollTop() >= 100) { // The Logo's above the topbar is 100px 
      $('div.topbar').css({
          position:"fixed",         // After the logo area disappear, fix the topbar at top:0
          'top':0,
          'left':0,
          'right':0
      });
    } else {
      $('div.topbar').css({'position':'relative'}); // Just below the logo area.
    }
  });
});