Sending flashvars in loader

Ok, I’ve got an already compiled swf I want to load into a project. The swf is the open source OpenZoom image zoomer. It works fine when it’s embedded in html embed tags with flashvars.

How do I load this swf into another flash swf and send it the correct vars? I routinely load a compiled swf into another swf. In this case, I tried to send it the var=‘something’ in the onComplete tag, but I get an init error.