var MMns4 = (document.layers)? true:false;
var MMie4 = (document.all)? true:false;
var MMdom = (document.getElementById)? true:false;

function showHideLayers() {
   var i,v,args=showHideLayers.arguments;
   for (i=0; i<(args.length-2); i+=3) {
      v=args[i+2];
      if (MMdom) {
         if (args[i+2]=='show') { v = 'visible'; } else { v = 'hidden'; }
         if (document.getElementById(args[i])!=null) { document.getElementById(args[i]).style.visibility = v;}
      } else if (MMie4) {
         if (args[i+2]=='show') { v = 'visible'; } else { v = 'hidden'; }
         if (document.all[args[i]]!=null) { document.all[args[i]].style.visibility = v; }
      } else if (MMns4) {
         if (args[i+2]=='show') { v = 'show'; } else { v = 'hidden'; }
         if (document.layers[args[i]]!=null) { document.layers[args[i]].visibility = v; }
      }
   }
}