. ", 
				" . intval($this->fetch_field("tagid")) . ",
				"	. $this->registry->userinfo['userid'] . ",
				" . TIMENOW . "
				)
		"); 
	}


	public function detach_content($type, $id) 
	{
		$this->dbobject->query_write("
			DELETE FROM " . TABLE_PREFIX . "tagcontent 
			WHERE entitytype = '" . $this->dbobject->escape_string($type) . "' AND 
				entityid = " . intval($id) . " AND
				tagid = " . intval($this->fetch_field("tagid")) 
		); 
	}

	/**
	*	Make this tag a synonym for another tag
	*
	*	Any associations between this tag and content will be transfered to the parent.
	*
	* @param int $canonical_id id for the tag that this will become the synonym of
	*/
	public function make_synonym($canonical_id) 
	{
		//if we already have synonyms attach them to the new canonical id as well
		//we only allow one level of synonyms
		foreach ($this->fetch_synonyms() as $synonym)
		{
			$synonym->make_synonym($canonical_id);
		}

		//actually make this a synonym
		$this->set("canonicaltagid", $canonical_id);
		$this->save();

		//fix any associated content items
		$associated_content = $this->fetch_associated_content();
		foreach ($associated_content as $contenttypeid => $contentids)
		{
			foreach ($contentids as $contentid)
			{
				$replace_threads[] = "($canonical_id, " . intval($contenttypeid) . ", $contentid, " . 
					$this->registry->userinfo['userid'] . ", " . TIMENOW . ")";
			}
		}

		// add new tag to affected threads
		if (sizeof($replace_threads))
		{	
			$this->dbobject->query_write("
				REPLACE INTO " . TABLE_PREFIX . "tagcontent (tagid, contenttypeid, contentid, userid, dateline) VALUES " .
				implode(',', $replace_threads) . "
			");
		}

		//clear old category associations.
		$this->dbobject->query_write("
			DELETE FROM " . TABLE_PREFIX . "tagcontent WHERE tagid = " . intval($this->fetch_field("tagid"))
		);

		$this->handle_associated_content_removals($associated_content);


		//update the tag search cloud datastore to reflect the change
		$this->dbobject->query_write("
			UPDATE " . TABLE_PREFIX . "tagsearch SET tagid = " . intval($canonical_id). " 
				WHERE tagid = " . intval($this->fetch_field("tagid"))
		);

		return true;
	}

	/**
	* Unlink a synonym from its canonical parent.
	*
	* This will not reestablish any relationships between the tag and content that
	* may have been transfered to the parent when the tag was made a synonym.
	*/
	public function make_independent() 
	{
		$this->set("canonicaltagid", 0);
		$this->save();
	}

	public function pre_save($doquery) 
	{
		if (!$this->condition AND !$this->fetch_field('dateline'))
		{
			$this->set('dateline', TIMENOW);
		}
		return true;
	}

	public function pre_delete($doquery)
	{
		$contentsql = "DELETE FROM " . TABLE_PREFIX . "tagcontent WHERE tagid = " . 
			intval($this->fetch_field("tagid"));

		$searchtagssql = "DELETE FROM " . TABLE_PREFIX . "tagsearch WHERE tagid = " . 
			intval($this->fetch_field("tagid"));


		//if we have synonyms for this tag, delete those as well.
		if ($doquery) 
		{
			foreach ($this->fetch_synonyms() as $synonym)
			{
				$synonym->delete();
			}

			$associated_content = $this->fetch_associated_content();	
			$this->dbobject->query_write($contentsql);
			$this->dbobject->query_write($searchtagssql);
			$this->handle_associated_content_removals($associated_content);
		}
		else 
		{
			//probably should log the other non sql actions
			$this->log_query($contentsql);
			$this->log_query($searchtagssql);
		}
		return true;
	}

	private function fetch_associated_content() 
	{
		$result = $this->dbobject->query_read("
			SELECT contenttypeid, contentid
			FROM " . TABLE_PREFIX . "tagcontent
			WHERE tagid = " . intval($this->fetch_field("tagid"))
		);

		$associated_content = array();
		while (list($contenttypeid, $contentid) = $this->dbobject->fetch_row($result))
		{
			$associated_content[$contenttypeid][] = $contentid;
		}
		$this->dbobject->free_result($result);
		return $associated_content;
	}

	/**
	*	Propogate any content specific effects for removing this tag from a content item
	*
	*	Some content tables may store the list of associated tags in as part of the record
	* in addition to the main association table.  While this is more efficient for lookups
	* we need to keep track of it when tags are removed.  This can happen because a tag 
	* was deleted or because it was replaced with another tag.
	*
	* @param Array $associated_content An array of the form 'contenttypeid' => 'contentids' 
	* 	containing all of the content ids associated with a particular tag
	*/
	private function handle_associated_content_removals($associated_content) 
	{
		//As we add additional content types, we should look at how this logic can be 
		//generalized

		// update thread taglists
		foreach ($associated_content as $contenttypeid => $contendids) 
		{
			foreach ($contendids as $contendid)
			{
				$item = vB_Taggable_Content_Item::create($this->registry, $contenttypeid, $contendid);
				if ($item)
				{
					$item->rebuild_content_tags();
				}
			}
		}
	}

	/*
		Should probably get moved to the base class, but I'm not quite ready to 
		do that.
	*/

	protected function load_existing() 
	{
		if ($this->condition) 
		{
			$fields = array_keys($