var SiteMap = new Class({ 

    initialize: function() {
    
        // hide all blocks initially
        $('sitemaptree').getElements('p').slide('hide');
        
        // look for h4 and p elements together (heading and content) and open
        // any which contain a span
        $('sitemaptree').getElements('h4').each(function(obj_header) {
        
            var obj_content = obj_header.getParent().getElement('p');
            
            if(obj_content.getElement('span.keyword') || obj_header.getElement('span.keyword')) {
            
                obj_header.addClass('open');
                obj_content.slide('in');
            }
        });

	    // allow blocks to be opened or closed
	    $('sitemaptree').getElements('h4').addEvent('click', this.toggle);
    },
    
    toggle: function(obj_event) {

        var elm_target = $(obj_event.target);
        var elm_content = elm_target.getParent().getElement('p');
        
        elm_target.toggleClass('open');
        elm_content.slide('toggle');
    }

});