....make a mc load only once> how to?

I have a mc onstate.swf that causes indirectly to load soundcentral.swf via
timeline of navbar.swf ;
as mc onstate.swf has to be reloaded several times this causes inconvenience to load soundcentral.swf everytime onstate.swf is loaded ;
is there a way to detect soundcentral.swf is already loaded and to avoid to load it again ?
cheers