window.addEvent('domready', function(){

    $$('.category').addEvent ('mouseover', function(o) {

		this.removeClass('categoryOff');
		this.addClass('categoryOn');

    });

    $$('.category').addEvent ('mouseout', function() {

		this.removeClass('categoryOn');
		this.addClass('categoryOff');

    });

    $$('.resource').addEvent ('mouseover', function(o) {

		this.removeClass('resourceOff');
		this.addClass('resourceOn');

    });

    $$('.resource').addEvent ('mouseout', function() {

		this.removeClass('resourceOn');
		this.addClass('resourceOff');

    });

});