$(document).ready(function(){
    //don't need z-index. append to the end of mainWindow to set als last element 
    $('.mainWindow').append($('ul#topnav').parent());

    function mOver() {
        $(this).find('.sub').stop().slideToggle("fast");
    }
    function mOut() {
        $(this).find('.sub').stop().slideToggle('fast', 0, function() {
            $(this).hide(); 
        });
    }
    
    var config = {    
         sensitivity: 2, // number = sensitivity threshold (must be 1 or higher)    
         interval: 100, // number = milliseconds for onMouseOver polling interval    
         over: mOver, // function = onMouseOver callback (REQUIRED)    
         timeout: 500, // number = milliseconds delay before onMouseOut    
         out: mOut // function = onMouseOut callback (REQUIRED)    
    };

    //$("ul#topnav li .sub").css({'opacity':'0'});
    $("ul#topnav li").hoverIntent(config);
});