Help on manipulating imported movies

question no 1:

I have a list of external movies. I want to import them only once and then use them as many times as I want. I need to attach them to other clips the same way I would attach them if they were in my current library with linkage option on.

question no 2:

suppose i have a movie called s1.swf in the same location with my movie.
then I have this code:

function createObj(objname, whichMc, level) {
_root.createEmptyMovieClip(objname, level);
_root[objname].createEmptyMovieClip("mc", 1);
_root[objname].mc.loadMovie(whichMc, "clipart", 1);
_root[objname].mc.onPress = function() {
createObj("tralala" , "s1.swf", 1, 150, 150);

I don’t know why the event handler for the movie “mc” is not invoked … I have no trace record in the outpus window. what is wrong with it?