Loading swf's

Hey peeps i allready asked this question couple of days ago but didn’t get the any further but i know have a sample of what i am talking about.
I guess it is just really simple but i cant get it to work.

http://www.rbk.com/us/basketball/

If you check this site and then click on the ballers button or any other button you will still see the active swf and the preloader will start preloading the new swf but still the old one will be visable till the new one is loaded how is this done ?

Hope my question is more clear now then the last time

Hmmm, Im thinking this. The actual background images are part of the main swf. Because the initial preload size says 513kb.
As far as the content, it loads into a container clip, once loaded, a varible is used to show one of the backgrounds. Then when the background is shown, the content is visible or is told to play its tiemline. Fairly simple build, and done with 99.99% of flash sites out there =)

thanks for your help