Convert Loaded swf to Movie Clip

programming flash
1

Hey,
Can someone help me with loading external swfs. I am trying to load a swf and I need to be able to access certain frames in the swf. I’ve tried:

loader.load(new URLRequest("intro.swf"));
loader.target.content.totalFrames;

to access the number of frames

and

loader.load(new URLRequest("intro.swf"));
test_mc.addChild(loader);

and neither method worked. Hopefully someone can explain how to add an swf to a movieclip. Thanks