(function ($) {
    var
        sfixed = {
            ui: {}
        },
        $sfixed = $(sfixed)
    ;
    window.ScrollFixed = sfixed;
    window.$ScrollFixed = $sfixed;
})(jQuery);
(function($,sfixed){
    sfixed.ui.autoVisible = function(selector,of){
        selector = $(selector);
        //var virtual = $('<div class="maskmainmenu">').css({
            //height: selector.height(),
            //visibility: 'hidden'
        //});
        var 
            css = $.extend(selector.position(),{height: selector.height(),position: 'absolute', left:0,right:0}),
            offset = selector.offset();
        ;
       // selector.before(virtual).css(css);
        
        of = $(of), isfix = false;
        of.scroll(function(e){
            var sTop = of.scrollTop();
            if(sTop > offset.top){
                isfix || selector.css({position: 'fixed',top: 0});
                isfix = true;
            }else{
                isfix && selector.css(css);
                isfix = false;
            } 
        });
    }
})(jQuery,ScrollFixed);