Image Gallery in AS3

When trying to migrate to AS3 i found a problem with my image gallery, and i need to know wich is the best way to do it now, before i used to duplicate movieclips and load the thumbs inside them, and for the preload thing, i used to have a preloader inside the movieclip duplicated, so i just tell each movieclip that onEnterFrame look for the loaded progress, but now i know i cant do it that way, does any know what would be my alternative, or maybe the right way to do it.