$(function() {

    function filterPath(string) {
    	return string
    	.replace(/^\//,'')
    	.replace(/(index|default).[a-zA-Z]{3,4}$/,'')
    	.replace(/\/$/,'');
    }

    var locationPath = filterPath(location.pathname);
    var scrollElem = scrollableElement('html', 'body');

    // Any links with hash tags in them (can't do ^= because of fully qualified URL potential)
    $('a[href*=#]').each(function() {

    	// Ensure it's a same-page link
    	var thisPath = filterPath(this.pathname) || locationPath;
    	if (  locationPath == thisPath
    		&& (location.hostname == this.hostname || !this.hostname)
    		&& this.hash.replace(/#/,'') ) {

    			// Ensure target exists
    			var $target = $(this.hash), target = this.hash;
    			if (target) {

    				// Find location of target
    				var targetOffset = $target.offset().top;
    				$(this).click(function(event) {

    					// Prevent jump-down
    					event.preventDefault();

    					// Animate to target
    					$(scrollElem).animate({scrollTop: targetOffset}, 1000, function() {

    						// Set hash in URL after animation successful
    						location.hash = target;

    					});
    				});
    			}
    	}

    });

    // Use the first element that is "scrollable"  (cross-browser fix?)
    function scrollableElement(els) {
    	for (var i = 0, argLength = arguments.length; i <argLength; i++) {
    		var el = arguments[i],
    		$scrollElement = $(el);
    		if ($scrollElement.scrollTop()> 0) {
    			return el;
    		} else {
    			$scrollElement.scrollTop(1);
    			var isScrollable = $scrollElement.scrollTop()> 0;
    			$scrollElement.scrollTop(0);
    			if (isScrollable) {
    				return el;
    			}
    		}
    	}
    	return [];
    }

});