var layer_V = 0, layer1_V = 0;

function Mostra(i)
{
 Esconde();
   eval('document.all.layer'+i+'.style').visibility="visible";
 layer_V = i;
}

function Mostra1(i)
{
 Esconde1();
   eval('document.all.layer'+i+'_1.style').visibility="visible";
 layer1_V = i;
}

function Esconde(i)
{
 if(layer_V<=0) return;
 
 if (layer_V != i)
   { 
     eval('document.all.layer'+layer_V+'.style').visibility="hidden";
   layer_V = 0;
   }
}

function Esconde1(i)
{
 if(layer1_V<=0) return;
 
 if (layer1_V != i)
   {
     eval('document.all.layer'+layer1_V+'_1.style').visibility="hidden";
   layer1_V = 0;
   }
}