mesocolumn main nav scroll fixed

function meso_float_primary_fixed() { ?>
<?php
if( is_user_logged_in() ) { $log = 'true'; } else { $log = 'false'; }
if( is_admin_bar_showing() ) { $abshow = 'true'; } else { $abshow = 'false'; } ?>
<script type="text/javascript">
jQuery.noConflict();
var $st = jQuery;
var log = <?php echo $log; ?>;
var abs = <?php echo $abshow; ?>;
$st(document).ready(function() {

    // grab the initial top offset of the navigation
    var sticky_navigation_offset_top = $st('#main-navigation').offset().top;

    // our function that decides weather the navigation bar should have "fixed" css position or not.
    var sticky_navigation = function(){
        var scroll_top = $st(window).scrollTop(); // our current vertical position from the top


        // if we've scrolled more than the navigation, change its position to fixed to stick to top, otherwise change it back to relative
        if (scroll_top > sticky_navigation_offset_top) {
        if( log == true ) {
        if( abs == true ) {
        $st('#main-navigation').css({ 'box-shadow': '0 0 10px #333','background-color': '#fff', 'z-index': '9999','position': 'fixed', 'padding': '0','top':30, 'left':0 });
        } else {
         $st('#main-navigation').css({ 'box-shadow': '0 0 10px #333','background-color': '#fff', 'z-index': '9999','position': 'fixed', 'padding': '0','top':0, 'left':0 });
        }

        } else {
        $st('#main-navigation').css({ 'box-shadow': '0 0 10px #333','background-color': '#fff','z-index': '9999','position': 'fixed','top':0, 'left':0 });
        }

        } else {
            $st('#main-navigation').css({ 'box-shadow': 'none','position': 'relative','padding': '0' });
        }

    };

    // run our function on load
    sticky_navigation();

    // and run it again every time you scroll
    $st(window).scroll(function() {
         sticky_navigation();
    });

    // NOT required:
    // for this demo disable all links that point to "#"
    $st('a[href="#"]').click(function(event){
        event.preventDefault();
    });

});
</script>
<?php }
add_action('wp_head','meso_float_primary_fixed',10);