function show(id) {
        document.getElementById("default_def").style.visibility = "hidden";
                                                                                                                                                      
        var div = document.getElementById('featuredefs');
        if (div == null) return false;
        if (!div.childNodes || div.childNodes.length == 0) return false;
                                                                                                                                                      
        for (var i=0;i<div.childNodes.length;i++) {
                var obj = div.childNodes[i];
                if (obj.nodeName==="DIV") { obj.style.visibility = "hidden";}
        }
                                                                                                                                                      
        document.getElementById(id).style.visibility = "visible";
}