Trouble with Preloading

I’m running into an error 1009 on a script that I’ve been working on. What I’m trying to do is attach a preloader Movie Clip that I have in my library with a class name of preloader, to an empty Movie Clip called preloaderMC and position that on a set of loaded thumbnail images. [see attached]

I can get the code to show one preloader and it will track the total of all the images being loaded, not single images. Ideally, I’d like the preloaders to show the amount loaded for each image and then disappear.

Any suggestions?