/**
 * hide_nav
 *
 * Hides the item in the nav bar that corresponds to the current page.
 *
 * @param   string  The full url of the current page.
 */
function hide_nav(href){
    var nav_items = $$('.nav a');
    nav_items.each(function(item, index){
        if(href == item.href){
            var parent = item.getParent();
            parent.style.display = 'none';
        }
    });
}