Launching and Detecting a Child SWF?

I have a project where a swf is going to call another swf via a url and the calling swf needs to detect when the child swf is done. The child will not have any means of communicating with the calling swf so the calling swf will need some means of launching the child and detecting when the child is exited (either by ending or the user closing it).

Below is the current code. flashThickBox throws an error because it apparently doesn't understand the format of the data passed to it.

flash.net.naviagetourl launches the child correctly but does not provide any means for detecting when the child is exited.

The url is https://website/directory/player.html which is a simple html page that loads player.swf. It has to be done in this format as we currently have older authorware files that need to be launched via this same method.