public function delete($id=false, $index, $type, array $options = array()) {
		$params = array( '_id' => $id, 
   					     '_index' => $index, 
					     '_type' => $type);

		foreach ($options as $key => $value) {
			$params['_' . $key] = $value;
		}

		$operation = array(
			array('delete' => $params)
		);
		$this->operations[] = $operation;
		return $this;

	}