function showhidelyr(lyr,sh) {
  var lyrhandle=false;
  if (document.layers) { // NS4
    lyrhandle = document.layers[0].layers[lyr];
    if (lyrhandle) {
      if (sh) { cmd="show"; } else { cmd="hide"; } lyrhandle.visibility=cmd;
    }
  }
  else if (document.all) { // IE4+ / OPStealth
    lyrhandle = document.all.tags("div")[lyr];
    if (lyrhandle) {
      if (sh) { cmd="visible"; } else { cmd="hidden"; } lyrhandle.style.visibility=cmd;
    }
  }
  else if (document.getElementById) { // MOZ / OP
    lyrhandle = document.getElementById(lyr);
    if (lyrhandle) {
      if (sh) { cmd="visible"; } else { cmd="hidden"; } lyrhandle.style.visibility=cmd;
    }
  }
  if (!lyrhandle) { alert(lyr+" not found."); }
}
function hidelyr(lyr) { showhidelyr(lyr,0); }
function showlyr(lyr) { showhidelyr(lyr,1); }
function reshowlyr(lyr) { hidelyr(lyr); showlyr(lyr); }
function hidetext(pers,spr,txt) {
  hidelyr(pers+"_Spr_"+spr);
  hidelyr(pers+"_Text_"+txt);
}
function showtext(pers,spr,txt) {
  showlyr(pers+"_Spr_"+spr);
  showlyr(pers+"_Text_"+txt);
}
function changetext(pers,alttxt,neutxt) {
  hidelyr(pers+"_Text_"+alttxt);
  showlyr(pers+"_Text_"+neutxt);
}