Hi. Try to go to module settings and ensure that "Fetch items from children categories" is set to "Yes".

thanks for the quick reply. 't work. module blank.

This seems like an issue on your logic. First of all modules don't work like that. Modules are cached. So when you visit the first category, the module will be cached and all the next pages will display the same output. Secondly, the code you provided will not work for menu links to multiple categories as there is no id parameter in the URL in that case.