function postJson($action,$json,$options = array()){
		if(!is_string($json)){
			$json = json_encode($json);
		}
		$options += array(
			"mime_type" => "application/json",
			"params" => array(),
		);
		$params = $options["params"];
		unset($options["params"]);
		return $this->postRawData($action,$json,$params,$options);
	}