Problems with loadMovie()

I am using the code that Kirupa provided in a tutorial on creating a photo gallery in Flash. On the website that I’m making, I have a “panel” that will house all of the pictures in my gallery, one picture at a time. The pictures contain various things such as figure drawings, renderings of 3d models and such. I wanted to make everything but the object in the photo itself totally transparent. For example, if I had a picture of a man standing upright with a solid black background, I want that solid black background to go away (become totally transparent) so only the man is visible. I have done so in Photoshop, but when I load the pictures into my photo gallery in Flash, the image is totally missing - in other words, the entire image is transparent. I then noticed that the loadMovie() function only accepts either .SWF or .JPEG files to load and JPEG’s don’t support any transparency. I need to use either PNG, GIF, TIFF or BMP. Anybody have any ideas on how I can get these images to display in such a manner??? For clarificiation, here is the code I used from the Kirupa photo gallery tutorial:

MovieClip.prototype.loadPhoto = function() {
	// specify the movieclip to load images into
	var p = _root.photo;
	//------------------------------------------
	p._alpha = 0;
	p.loadMovie(this.pathToPics+this.pArray[this.pIndex]);
	this.onEnterFrame = loadMeter;
};
MovieClip.prototype.loadMeter = function() {
	var i, l, t;
	l = this.photo.getBytesLoaded();
	t = this.photo.getBytesTotal();
	if (t>0 && t == l) {
		this.onEnterFrame = fadeIn;
	} else {
		trace(l/t);
	}
};