echo '<li class="' . $ni->classes . '">'; //opens a nav item

if ($ni->cObj->vObj->ctHandle == "pb_post") {
   echo '<li class="hidden">'; 
} else {
   echo '<li class="' . $ni->classes . '">'; //opens a nav item
}

.hidden {
  display: none;
}

$('.hidden').remove();
  $('nav ul').each(function(){
    if ($(this).is(':empty')) {
      $(this).remove();
    }
  });

foreach($aBlocks as $ni)

//This is sort of a hack, but we'll remove any blocks whose parent
//has an "exclude_nav_children" attribute set to true
foreach($aBlocks as $outer) {
   $outerCollection = $outer->getCollectionObject();
   if ($outerCollection->getCollectionAttributeValue('exclude_nav_children')) {
      //This item is set to exclude children. Let's find and remove them
      $targetId = $outerCollection->cID;
      $count = 0;
      foreach($aBlocks as $inner) {
         $innerCollection = $inner->getCollectionObject();
         //Found one! Let's nix it.
         if ($innerCollection->getCollectionParentID() == $targetId) {
            unset($aBlocks[$count]);
         }
         $count++;