function hideLayer(whichLayer) {

if (document.getElementById) {
document.getElementById(whichLayer).style.visibility = "hidden";
}

else if (document.all) {
document.all[whichlayer].style.visibility = "hidden";
}

else if (document.layers) {
document.layers[whichLayer].visibility = "hidden";
}

}

function showLayer(whichLayer) {

if (document.getElementById) {
document.getElementById(whichLayer).style.visibility = "visible";
}

else if (document.all) {
document.all[whichlayer].style.visibility = "visible";
}

else if (document.layers) {
document.layers[whichLayer].visibility = "visible";
}

}

function handleClick(whichClick, name) {
var teile= name.split(",");
if (whichClick == "hide it") {
  for (i=0;i<teile.length;i++) hideLayer(teile[i]);
}
else if (whichClick == "show it") {
  for (i=0;i<teile.length;i++) showLayer(teile[i]);
}

}