function cerrar_ventana() {
  document.write('<a href="#" onclick="window.close();" onkeypress="window.close();">cerrar</a>');
 }
 
 function etiqueta(nombre){
  if (document.layers){
   document.layers["politicas"].zIndex=-1;
   document.layers["politicas"].visibility="hidden";
   document.layers["mbasicos"].zIndex=-1;
   document.layers["mbasicos"].visibility="hidden";
   document.layers["mespecificos"].zIndex=-1;
   document.layers["mespecificos"].visibility="hidden";
   document.layers["pgenerales"].zIndex=-1;
   document.layers["pgenerales"].visibility="hidden";
   document.layers["ptecnicos"].zIndex=-1;
   document.layers["ptecnicos"].visibility="hidden";
   document.layers["itecnicas"].zIndex=-1;
   document.layers["itecnicas"].visibility="hidden";
   document.layers["etecnicas"].zIndex=-1;
   document.layers["etecnicas"].visibility="hidden";
   document.layers["guias"].zIndex=-1;
   document.layers["guias"].visibility="hidden";
  }else{
   document.all.politicas.style.zIndex=-1;
   document.all.politicas.style.visibility="hidden";
   document.all.mbasicos.style.zIndex=-1;
   document.all.mbasicos.style.visibility="hidden";
   document.all.mespecificos.style.zIndex=-1;
   document.all.mespecificos.style.visibility="hidden";
   document.all.pgenerales.style.zIndex=-1;
   document.all.pgenerales.style.visibility="hidden";
   document.all.ptecnicos.style.zIndex=-1;
   document.all.ptecnicos.style.visibility="hidden";
   document.all.itecnicas.style.zIndex=-1;
   document.all.itecnicas.style.visibility="hidden";
   document.all.etecnicas.style.zIndex=-1;
   document.all.etecnicas.style.visibility="hidden";
   document.all.guias.style.zIndex=-1;
   document.all.guias.style.visibility="hidden";
  }

 if (nombre=="politicas"){
  if (document.layers){
   document.layers["politicas"].zIndex=1;
   document.layers["politicas"].visibility="visible";
  }else{
   document.all.politicas.style.zIndex=1;
   document.all.politicas.style.visibility="visible";
  }
 }

 if (nombre=="mbasicos"){
  if (document.layers){
   document.layers["mbasicos"].zIndex=1;
   document.layers["mbasicos"].visibility="visible";
  }else{
   document.all.mbasicos.style.zIndex=1;
   document.all.mbasicos.style.visibility="visible";
  }
 }

 if (nombre=="mespecificos"){
  if (document.layers){
   document.layers["mespecificos"].zIndex=1;
   document.layers["mespecificos"].visibility="visible";
  }else{
   document.all.mespecificos.style.zIndex=1;
   document.all.mespecificos.style.visibility="visible";
  }
 }
 
 if (nombre=="pgenerales"){
  if (document.layers){
   document.layers["pgenerales"].zIndex=1;
   document.layers["pgenerales"].visibility="visible";
  }else{
   document.all.pgenerales.style.zIndex=1;
   document.all.pgenerales.style.visibility="visible";
  }
 }
 
 if (nombre=="ptecnicos"){
  if (document.layers){
   document.layers["ptecnicos"].zIndex=1;
   document.layers["ptecnicos"].visibility="visible";
  }else{
   document.all.ptecnicos.style.zIndex=1;
   document.all.ptecnicos.style.visibility="visible";
  }
 }
 
 if (nombre=="itecnicas"){
  if (document.layers){
   document.layers["itecnicas"].zIndex=1;
   document.layers["itecnicas"].visibility="visible";
  }else{
   document.all.itecnicas.style.zIndex=1;
   document.all.itecnicas.style.visibility="visible";
  }
 }
 
 if (nombre=="etecnicas"){
  if (document.layers){
   document.layers["etecnicas"].zIndex=1;
   document.layers["etecnicas"].visibility="visible";
  }else{
   document.all.etecnicas.style.zIndex=1;
   document.all.etecnicas.style.visibility="visible";
  }
 }
 
 if (nombre=="guias"){
  if (document.layers){
   document.layers["guias"].zIndex=1;
   document.layers["guias"].visibility="visible";
  }else{
   document.all.guias.style.zIndex=1;
   document.all.guias.style.visibility="visible";
  }
 }   

}