URGENT: Disabling Captivate navigation from child swf

I'm using Captivate 7 to publish some courseware in swf format, which will be launched through an html page.

On one of my slides, I have an embedded swf, which I'll refer to as the child. In the child, I need the user to complete some action correctly before they can progress to the next slide.

When the slide is first entered, the functionality of the next slide button is disabled through a conditional check of a variable 'NextLocked'. I'd like to be able to modify the value of this variable from the child after the user has completed the appropriate actions.

I've tried making calls from the child like

  var p:MovieClip = this.parent.parent.parent as MovieClip;

  p.NextLocked = true;

But the variable in the parent is not being updated. I've also tried increasing the number of '.parent' (var p:MovieClip = this.parent.parent.parent.parent.parent as MovieClip; etc) accessors in the child, but nothing has worked so far.

Is this something that can be done, and if so, how would I do it?

If someone knows that this is definitely NOT possible, could you state such?

I'm also willing for an alternate solution (making the child move the main swf to the next slide, relying on external javascript, etc).

Any help is much appreciated.