问jQuery下拉菜单在IE和Webkit中的行为不同

EN

$(function() {
/* for keeping track of what's "open" */
    var activeClass = 'menu-open', showingDropdown, showingMenu, showingParent;
    /* hides the current menu */
    var hideMenu = function() {
        if(showingDropdown) {
            showingDropdown.removeClass(activeClass);
            showingMenu.fadeOut(500);
        }
    };

    /* recurse through dropdown menus */
    $('.drop').each(function() {
        /* track elements: menu, parent */
        var dropdown = $(this);
        var menu = dropdown.next('.subnav'), parent = dropdown.parent();
        /* function that shows THIS menu */
        var showMenu = function() {
            hideMenu();
            showingDropdown = dropdown.addClass('menu-open');
            showingMenu = menu.show();
            showingParent = parent;
        };
        /* function to show menu when clicked */
        dropdown.attr('href','/#dropdown').bind('click',function(e) {
            if(e) e.stopPropagation();
            if(e) e.preventDefault();
            if ( dropdown.hasClass('menu-open') ) {
                hideMenu();
            } else {
                showMenu();
            }
        });
        /* function to show menu when someone tabs to the box */
        dropdown.bind('focus',function() {
            showMenu();
        });

    });
});