Fixed the menu to the top of the page on scroll down

This is the simplest to fix menu on the top of the page when the content on scroll down
<script type="text/javascript">
var fixed_menu_hidden = true;
function dtbaker_scroll(){
var scrollTop = $(window).scrollTop();
if(scrollTop>380){
if(fixed_menu_hidden){
$('#menu-top').css('margin-top',0);
fixed_menu_hidden = false;
}
}else{
$('#menu-top').css('margin-top',-75);
fixed_menu_hidden = true;
}
}
window.onscroll = dtbaker_scroll;
$(function(){});
</script>

<style type="text/css">
#menu-top {
position:fixed;
left:0;
right:0;
top:0;
height:39px;
background:#13B8D6;
z-index:300;
margin-top: -75px;
}

Bilder: online-nrw.de