gistfile1.js

(function($) {
	$.fn.accessibleTabs = function(){
		return this.each(function(e) {
			var $el = $(this);
		
			$el.find("li").keydown(function(e) {
				var $el = $(this),
					$prevTab = $el.prev().find('a'),
					$nextTab = $el.next().find('a'),
					$first = $el.parent().find("li:first a"),
					$last = $el.parent().find("li:last a");
				
				switch (e.which) {
					case 37:
					case 38:		
						if($prevTab.length) {
							$prevTab.trigger('click').focus();
						} else {
							$last.trigger('click').focus();
						}
						e.preventDefault();
						break;
					case 39: 
					case 40:
						if($nextTab.length) {
							$nextTab.trigger('click').focus();
						} else {
							$first.trigger('click').focus();
						}
						e.preventDefault();
						break;
				}
			});
		
			$el.find("a").click(function(e) {
				var $el = $(this),
					$tab = $el.parent(),
					$targetPage = $($el.attr('href'));
			
				$el.attr({
					'tabindex': 0,
					'aria-selected': "true"
				});
			
				$targetPage
					.show()
					.siblings()
						.hide();
			
				$tab
					.addClass('current')
					.siblings()
						.removeClass('current')
						.find('a')
							.attr({
								'tabindex': -1,
								'aria-selected': "false"
							});
			
				e.preventDefault();
			});
		
			$('[role="tabpage"]').not(':first').hide();
		});
	};
})(jQuery);