<!--
nbr_layer = 3;

function cache_all(){
if(document.all){
  for(var i=1;i<nbr_layer+1;i++){
          						if((Math.round(i/2)*2)==i){
          												  document.all("r"+i).style.visibility = (i==0)?"visible":"hidden"; 
          												  document.all("r"+0).style.visibility = (i==0)?"visible":"hidden";
                      									  }
         						}
    			}
else{
 	if(document.layers){
   	  for(var i=1;i<nbr_layer+1;i++){
              						if((Math.round(i/2)*2)==i){
              												  document.layers["r"+i].visibility =  (i==0) ?"show":"hide"; 
            												  document.layers["r"+0].visibility =  (i==0) ?"show":"hide";
															  }
             		   				}
    				   }
else{
    if(!document.all && document.getElementById){
      for(var i=1;i<nbr_layer+1;i++){
            						if((Math.round(i/2)*2)==i){
              												  document.getElementById("r"+i).style.visibility = (i==0)?"visible":"hidden"; 
              												  document.getElementById("r"+0).style.visibility = (i==0)?"visible":"hidden";
                      										  }
           							}
                   								}
    }
 	}
}
 
function show(n){
if(document.all){
  				for(var i=1;i<nbr_layer+1;i++){
          									  if((Math.round(i/2)*2)==i){
														  				document.all("r"+i).style.visibility = (i==n)?"visible":"hidden"; 
														  				document.all("r"+0).style.visibility = (i==i)?"visible":"hidden";
                  										  				}
         									  }
    			}
else{
 	if(document.layers){
     				   for(var i=1;i<nbr_layer+1;i++){
              										 if((Math.round(i/2)*2)==i){
 																			   document.layers["r"+i].visibility = (i==n)?"show":"hide"; 
 																			   document.layers["r"+0].visibility = (i==i)?"show":"hide";
                   									 						   }
             		   								 }
    				   }
else{
  if(!document.all && document.getElementById){
    										  for(var i=1;i<nbr_layer+1;i++){
            					 											if((Math.round(i/2)*2)==i){
              																document.getElementById("r"+i).style.visibility = (i==n)?"visible":"hidden"; 
              																document.getElementById("r"+0).style.visibility = (i==i)?"visible":"hidden";
                      																				  }
           																	}
                   							  }
    }
    }
}

//-->