if (navigator.appName == "Netscape") {
        document.writeln("<link rel=\"stylesheet\" href=\"n-style.css\" type=\"text/css\">");
}
if (navigator.appName == "Microsoft Internet Explorer") {
        document.writeln("<link rel=\"stylesheet\" href=\"e-style.css\" type=\"text/css\">");
}
if (navigator.appName == "Opera") {
        document.writeln("<link rel=\"stylesheet\" href=\"o-style.css\" type=\"text/css\">");
}

ns4 = (document.layers)? true:false;
ie4 = (document.all)? true:false;

function show(id) {
        hideAll();
        if (ns4) document.layers[id].visibility = "show";
        else if (ie4) document.all[id].style.visibility = "visible";
        }
function hide(id) {
        if (ns4) document.layers[id].visibility = "hide";
        else if (ie4) document.all[id].style.visibility = "hidden";
        }
function hideAll() {
        hide('submenu1');
        hide('submenu2');
        hide('submenu3');
        hide('submenu4');
}