function showhide(layer_ref) { 
  if (state == 'block') { 
    state = 'none'; 
  } 
  else { 
    state = 'block'; 
  } 
  if (document.all) { //IS IE 4 or 5 (or 6 beta) 
    eval( "document.all." + layer_ref + ".style.display = state"); 
  } 
  if (document.layers) { //IS NETSCAPE 4 or below 
    document.layers[layer_ref].display = state; 
  } 
  if (document.getElementById &&!document.all) { 
    hza = document.getElementById(layer_ref); 
    hza.style.display = state; 
  }

  var today = new Date();
  today.setTime( today.getTime() );
  var expires
  expires = 365 * 1000 * 60 * 60 * 24;
  var expires_date = new Date( today.getTime() + (expires) );
  document.cookie = "ShowComment=" +escape( state ) +
  ( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" );
} 

function confirmDelCom() {
  var agree=confirm("U staat op het punt dit commentaar\nte verwijderen! Is dit de bedoeling?");
  if (agree)
    return true ;
  else
    return false ;
}

function FI(input){
  var num = input.value.replace(/\,/g,'');
  if(!isNaN(num)){
    if(num.indexOf('.') > -1) {
      alert('U kunt geen decimalen invullen.');
      input.value = input.value.substring(0,input.value.length-1);
    }
  } else {
    alert('U kunt alleen maar nummers invullen');
    input.value = input.value.substring(0,input.value.length-1);
  }
}