		<!-- Inizio Codice index-->

function tess1(){
  document.getElementById("layer1").style.visibility= "visible";
}
function tess2(){
  document.getElementById("layer2").style.visibility= "visible";
}
function tess3(){
  document.getElementById("layer3").style.visibility= "visible";
}
function tess4(){
  document.getElementById("layer4").style.visibility= "visible";
}
function tess5(){
  document.getElementById("layer5").style.visibility= "visible";
}
function tess6(){
  document.getElementById("layer6").style.visibility= "visible";
}
function tess7(){
  document.getElementById("layer7").style.visibility= "visible";
}
function tess8(){
  document.getElementById("layer8").style.visibility= "visible";
}
function tess9(){
  document.getElementById("layer9").style.visibility= "visible";
}
function tess10(){
  document.getElementById("layer10").style.visibility= "visible";
}
function tess11(){
  document.getElementById("layer11").style.visibility= "visible";
}
function tess12(){
  document.getElementById("layer12").style.visibility= "visible";
}

		<!-- fine Codice index -->