var capa;
 

 
ns4 = (document.layers)? true:false
 
ie4 = (document.all)? true:false
 
ff=false;
 
if(!ns4 && !ie4){ff=true;}
 

 var mostrado = new Array();
 
 
 
function muestra(num) {
 
 var capa = new Array();
 
 var i;
 
 var txt_ini = true;
 
 for(i=1;i<=num_elementos;i++){
 
  capa[i]=('capa_'+i);
 
  if (ns4) {elemento = document.layers(capa[i]);}
 
  if (ie4) {elemento = document.all(capa[i]).style;}
 
  if (ff) {elemento = document.getElementById(capa[i]).style;}
 
  
 
  if(i==num){
 
   if (mostrado[i]==num){
	   	elemento.display = "none"; 
		mostrado[i]="";
   }else{
 
    mostrado[i]=num;
    elemento.display = "block";
   }
 
  }else{
 mostrado[i]="";
   elemento.display = "none";
 
  }
 }
 
}