@Schelbert: I don’t know where did you got that script and css. I hope it works fine. So, consult with your developer.
1. You can add script in “Appearance => Theme Options => Webmaster Tools => Header and Footer Codes” box:
<script>
jQuery(document).ready(function($) {
$(window).scroll(function () {
if ($(window).scrollTop() > 100) {
$('header').addClass('shrink');
}
else{
$('header').removeClass('shrink');
}
});
});
</script>
2. Then you can add your css in “Appearance => Theme Options => Custom CSS”
header.shrink {
position:fixed;
clear:both!important;
width:100%;
height:50px!important;
max-height:50px!important;
min-height:50px!important;
z-index:999999999;
transition: all 0.5s ease-in-out;
-moz-transition: all 0.5s ease-in-out;
-webkit-transition: all 0.5s ease-in-out;
-o-transition: all 0.5s ease-in-out;
}