Trying to recreate loadmovie with As3......addchild problems

I want to load in external swfs into an mc on the root called ‘holder’.

In As2, I would just do loadMovie(“whatever.swf”, this.holder);

And if I loaded another swf into that same holder it would replace the contents with the new swf.

But now, I’m trying As3 and doing…
var i =new Loader();
i.load(new URLRequest(“contact.swf”));

When I repeat this code, for another external swf, I want it to replace the first one, but it appears to not be doing that. I fear that this addChild, is simply adding more mc’s within my main holder mc.

So I don’t know how to match the functionality that I liked from As2. Help?