Duplicating MCs at Mouse position?

Hi all, sorry to ask such a basic question. Took a break from AS and now struggling to get back into it!

Im trying to create a spraycan that when the user holds down the left mouse button, creates foam movieclips at its point.

Im using startdrag to enable the can to be a cursor.

I was trying to put some script to the actual foam MC and have it triggering on mousedown. I guess Im not getting the code right:

onClipEvent(mouseDown) {

mc_foam.duplicateMovieClip("newfoam"+i, i);
     _root["newfoam"+i]._x=_xmouse;
 _root["newfoam"+i]._y=_ymouse;

}

No luck! Any ideas would be appreciated.