From taking a look at the other examples I've located the javascript that takes care of that for you. They use jQuery. Here is the code, Sorry it's long:
/*
*
* Fold/unfold header
*
*/
var snapped = false;
function fixHeader(){
$('#headercontainer, body').addClass('fixed')
}
function headerUnfold(){
$("header").animate({
"height" : 157
},300, "swing");
//if header is fixed
if($('body.fixed').length && !snapped){
$('#content').animate({
'margin-top' : 185
},300, "swing");
}
if($('body.fixed').length && snapped){
$('#submenucontainer').animate({
'margin-top' : 90
},300, "swing");
}
$("nav, #menu_aux").fadeIn('fast');
$("#menuback").hide();
$("header").bind('mouseleave' , function(){
headerFold(true);
})
}
function headerFold(animate){
$("header").unbind('mouseleave');
if(animate){
time = 300;
}else{
time = 0;
}
$("header").animate({
"height" : 65
},time, "swing")
//if header is fixed
if($('body.fixed').length && !snapped){
$('#content').animate({
'margin-top' : 80
},300, "swing");
}
if($('body.fixed').length && snapped){
$('#submenucontainer').animate({
'margin-top' : 0
},300, "swing");
}
if(animate){
$("nav, #menu_aux").fadeOut('fast');
}else{
$("nav, #menu_aux").hide();
}
$("#menuback").css({
"left" : -10
}).show().animate({
"left" : 20
},time)
}
$("#menuback").bind('mouseenter', function(){
headerUnfold();
})
Just make the element that you want the effect for id submenucontainer
. If you want a more direct link to the JS here it is.