var browserType;

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

function over(num) {
  if(document.images) {
    document.images[num].src = document.images[num].src.replace("_off", "_on");
  }
}
function out(num) {
  if(document.images) {
    document.images[num].src = document.images[num].src.replace("_on", "_off");
  }
}

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

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