function onoff(nr) {

if(document.layers) {

for(i = 0; i <= 7; i ++) {  document.layers[i].visibility="hide";  }
if(nr != 0) {  document.layers[nr-1].visibility="show";  }

} else if(document.getElementById) {

for(i = 1; i <= 9; i ++) {  document.getElementById("m"+i).style.display="none";  }
if(nr != 0) {  document.getElementById("m"+nr).style.display="block";  }

} else {

for(i = 1; i <= 9; i ++) {  document.all["m"+1].style.display="none";  }
if(nr != 0) {  document.all["m"+nr].style.display="block";  }

}
}