var browserType;

if (document.layers) {browserType = "nn4"}
if (document.all) {browserType = "ie"}
if (window.navigator.userAgent.toLowerCase().match("gecko")) {
   browserType= "gecko"
}

function hide(mylayer) {
  if (browserType == "gecko" )
     document.poppedLayer =
         eval('document.getElementById(mylayer)');
  else if (browserType == "ie")
     document.poppedLayer =
        eval('document.all[mylayer]');
  else
     document.poppedLayer =
        eval('document.layers[mylayer]');
  document.poppedLayer.style.visibility = "hidden";
}

function show(mylayer) {
  if (browserType == "gecko" )
     document.poppedLayer =
         eval('document.getElementById(mylayer)');
  else if (browserType == "ie")
     document.poppedLayer =
         eval('document.all[mylayer]');
  else
     document.poppedLayer =
         eval('document.layers[mylayer]');
  document.poppedLayer.style.visibility = "visible";
}