var currentLayer=10;

function updateLayer(newLayer){
var dummyLayer=currentLayer-11;
if (ns) { eval("document.layers['layer"+currentLayer+"'].visibility = 'hidden'"); }
else { eval("document.all['layer"+currentLayer+"'].style.visibility = 'hidden'"); }
if (dummyLayer>-1) {
 if (ns) { eval("document.layers['layer"+dummyLayer+"'].visibility = 'hidden'"); }
 else { eval("document.all['layer"+dummyLayer+"'].style.visibility = 'hidden'"); }
}
currentLayer=newLayer;
dummyLayer=currentLayer-11
if (ns) { eval("document.layers['layer"+currentLayer+"'].visibility = 'visible'"); }
else { eval("document.all['layer"+currentLayer+"'].style.visibility = 'visible'"); }
if (dummyLayer>-1) {
 if (ns) { eval("document.layers['layer"+dummyLayer+"'].visibility = 'visible'"); }
 else { eval("document.all['layer"+dummyLayer+"'].style.visibility = 'visible'"); }
}
}