Access External Movie

Hi:

I would like to set height after I load an external movie into a movie clip.

For example,

this.body_mc.loadMovie(“body_about.swf”);
_root._height = this.body_mc._height;

Does these make sense?
I always get height as 0, because body_mc is an empty movieClip.

Can anyone help me on how to access the body_about.swf height as soon as loaded the movie into the empty movie clip? Any suggesstion?

Thanks