flash - Load child swf with flashvars from parent swf -

I have to load another SWF from my SWF and I have to give them a flashwire feature, how can I do this?

I tried to do this but it is not working:

  loader.load (new URLRequest (url + "id = 33"));  

Do not you forget a question mark?

loader.load (new URLRequest (url + "? Id = 33"));