Expanding navigation keep open on page refresh

I found this code on line to make the navigation in the margin to expand and collapse. I need a way to set a cookie to keep the menu open when the page refreshes. Anyone know how to do this?

(function($) {

	$(document).ready(function() {

		$(".wpsc_top_level_categories > li:has(li)").prepend("<span class=\"CatExpander\">+</span>");
		$(".wpsc_top_level_categories").css( 'cursor', 'pointer' );

		$(".CatExpander").toggle(function() {

			$(this).html( '-' );

			}, function() {

			$(this).html( '+' );

		});

			$(".wpsc_top_level_categories li a").click(function() {

			$(this).toggleClass("CatExpanded").siblings(".CatExpander").toggle();//toggles the +
			$(this).toggleClass("CatExpanded").siblings("ul").slideToggle(500);

		}).eq(500).addClass("CatExpanded").end().slice(0).siblings("ul").hide(); 

$(".wpsc_top_level_categories > li:has(li)").hover(function () {
     $(this).children("a").click(function () {
        return false;
     });
  });

	});

})(jQuery);

https://wordpress.org/plugins/wp-e-commerce/