flashing boxes

It seems like on almost every flash site nowadays there are the new trendy flashing white boxes similar to the flashing white "boxes" in the navigation and the main frame of http://www.2advanced.com/flashindex.htm. I've tried and tried to replicate these flashy things, but they never look good.
What's the secret? Anyone know?

Thanks

I think things like that can be done by increasing the brightness at a certain frame.

But hey, I never work with flash.

If you want to do it in flash, just have a small movie with two frames, one with the default brightness, and one with the brighter brightness. Make sure it loops.

You can do that easily with GIFs too, just the same way.

oh it's just brightness? I thought they were just a bunch of graphic vector shapes covering objects with various alpha settings...?

I guess the brightness property would be easier.

That is Cool ,But It's very older.hoho~~`