Make targeted elements scroll with the window

squire.js

/**
 * Squire v1.0
 * Make targeted elements scroll with the window
 * by Arthur Corenzan <arthur@corenzan.com>
 * Creative Commons-Attribution-Share Alike
 * http://creativecommons.org/licenses/by-sa/3.0
 *
 * Under development...
 */
(function($) {
    $.fn.squire = function(o) {

        o = $.extend({
            classname: "fixed"
        }, o);
        
        var squires = [],
        $win = $(window);

        if($.browser.msie && $.browser.version == "8.0") {
            alert("IE8");
            $(document).add("html, body");
        }

        $win.scroll(function(e) {
            var i;

            for(i in squires) {
                if(squires.hasOwnProperty(i)) {

                    //if it scrolled past the threshold and is not fixed
                    if($win.scrollTop() > squires[i].offsetTop &&
                      !squires[i].hasClass(o.classname)) {
                        squires[i].addClass(o.classname);

                    //if it still over the threshold and is fixed
                    } else if($win.scrollTop() < squires[i].offsetTop && 
                      squires[i].hasClass(o.classname)) {
                        squires[i].removeClass(o.classname);
                    }
                }
            }
        });
        
        return this.each(function(i, that) {
            var $that = $(that);
            $that.offsetTop = $that.offset().top;
            squires.push($that);
        });
    };
})(jQuery);