Many sites use tree-like navigation menus in the design approach, but most of these tree controls reload all content of the page to expand/collapse levels. You can avoid it in your site with COOLjsTree. COOLjsTree can expand/collapse unlimited levels of the tree without reload. COOLjsTree does not require FRAME or IFRAME tag for work. You can configure the tree through the CSS and setup individual items parameters in the JavaScript configuration file or you can use our On-line Tree Builder to setup tree structure.