function OpenClose(anchor, id) {
  var cell = document.getElementById( "vraag" + id );
  if ( cell != null ){
    if ( anchor.className == "Open"  ) {
      anchor.className = "Close";
      cell.style.display = "none";
    } else {
      anchor.className = "Open";
      cell.style.display = "block";
    }
  }
}