function ShowHideLayers() { //v9.0
  var i,p,v,obj,args=ShowHideLayers.arguments;
  for (i=0; i<(args.length-2); i+=3) 
  with (document) if (getElementById && ((obj=getElementById(args[i]))!=null)) { v=args[i+2];
    if (obj.style) { obj=obj.style; v=(v=='show')?'block':(v=='hide')?'none':v; }
    obj.display=v; }
}

function changeValue(def_val, sender) {
    if (sender.value == def_val) {
        sender.value = "";
    } else if (sender.value == "") {
        sender.value = def_val;
    }
}