function switchnav(val){

  if (nNAV = document.getElementById("p"+val)){
    
    nNAV.className = (nNAV.className == 'closed')? 'open' : 'closed';
    
  }
}


function revert(sNum){
  if (document.getElementById(sNum+1)){
    
    n1 = document.getElementById(sNum+1).style;
    n2 = document.getElementById(sNum+2).style;
    n1.display = (n1.display == 'block')? 'none' : 'block';
    n2.display = (n2.display == 'block')? 'none' : 'block';
    
  }
}