var NN4;
var IE4;
var W3C;

if (document.layers) {
   NN4 = true;
   IE4 = false;
   W3C = false;
} else if (document.all) {
   NN4 = false;
   IE4 = true;
   W3C = false;
} else {
   W3C = true;
   NN4 = false;
   IE4 = false;
}

function show(layerName) {

   if (W3C) {
      document.getElementById(layerName).style.visibility = "visible";
   } else if (IE4) {
      document.all[layerName].style.visibility = "visible";
   } else if(NN4) {
      document.layers[layerName].visibility = "visible";
   }

}


function hide(layerName) {

   if (layerName == "all") {

      if (W3C) {

         document.getElementById('menu_name_home').className = "menu_name_out";
         document.getElementById('menu_name_about_nc').className = "menu_name_out";
         document.getElementById('menu_name_admissions').className = "menu_name_out";
         document.getElementById('menu_name_academics').className = "menu_name_out";
         document.getElementById('menu_name_events').className = "menu_name_out";
         document.getElementById('menu_name_guidance').className = "menu_name_out";
         document.getElementById('menu_name_events').className = "menu_name_out";
         document.getElementById('menu_name_student_life').className = "menu_name_out";
         document.getElementById('menu_name_parents').className = "menu_name_out";
         document.getElementById('menu_name_alumni').className = "menu_name_out";

         document.getElementById('menu_about_nc').style.visibility = "hidden";
         document.getElementById('menu_admissions').style.visibility = "hidden";
         document.getElementById('menu_academics').style.visibility = "hidden";
         document.getElementById('menu_guidance').style.visibility = "hidden";
         document.getElementById('menu_events').style.visibility = "hidden";
         document.getElementById('menu_student_life').style.visibility = "hidden";
         document.getElementById('menu_parents').style.visibility = "hidden";
         document.getElementById('menu_alumni').style.visibility = "hidden";

      } else if (IE4) {

         document.all['menu_name_home'].className = "menu_name_out";
         document.all['menu_name_about_nc'].className = "menu_name_out";
         document.all['menu_name_admissions'].className = "menu_name_out";
         document.all['menu_name_academics'].className = "menu_name_out";
         document.all['menu_name_guidance'].className = "menu_name_out";
         document.all['menu_name_events'].className = "menu_name_out";
         document.all['menu_name_events'].style.className = "menu_name_out";
         document.all['menu_name_student_life'].className = "menu_name_out";
         document.all['menu_name_parents'].className = "menu_name_out";
         document.all['menu_name_alumni'].className = "menu_name_out";

         document.all['menu_about_nc'].style.visibility = "hidden";
         document.all['menu_admissions'].style.visibility = "hidden";
         document.all['menu_academics'].style.visibility = "hidden";
         document.all['menu_guidance'].style.visibility = "hidden";
         document.all['menu_events'].style.visibility = "hidden";
         document.all['menu_student_life'].style.visibility = "hidden";
         document.all['menu_parents'].style.visibility = "hidden";
         document.all['menu_alumni'].style.visibility = "hidden";

      } else if(NN4) {

         document.layers['menu_name_home'].className = "menu_name_out";
         document.layers['menu_name_about_nc'].className = "menu_name_out";
         document.layers['menu_name_admissions'].className = "menu_name_out";
         document.layers['menu_name_academics'].className = "menu_name_out";
         document.layers['menu_name_guidance'].className = "menu_name_out";
         document.layers['menu_name_events'].className = "menu_name_out";
         document.layers['menu_name_student_life'].className = "menu_name_out";
         document.layers['menu_name_parents'].className = "menu_name_out";
         document.layers['menu_name_alumni'].className = "menu_name_out";

         document.layers['menu_about_nc'].visibility = "hidden";
         document.layers['menu_admissions'].visibility = "hidden";
         document.layers['menu_academics'].visibility = "hidden";
         document.layers['menu_guidance'].visibility = "hidden";
         document.layers['menu_events'].visibility = "hidden";
         document.layers['menu_student_life'].visibility = "hidden";
         document.layers['menu_parents'].visibility = "hidden";
         document.layers['menu_alumni'].visibility = "hidden";
      }

   }

}