Help with this zooming code?

I know enough about coding to read this (more or less), but what I lack is the knowledge to switch it to better suit my needs.
What I’m wanting is for this code to effect only the MC it’s attached to and to leave the rest of the movie alone. As it is now, you can click anywhere on the stage and it will zoom to those coordinates, as well as rendering my other “clickables” inoperable. Can anyone help me?

onClipEvent (mouseDown) {
if (k>0) {
return;
}
zoom = true;
dir == 1 ? (dir=-1) : (dir=1);
if (dir == 1) {
pt = {x:_root._xmouse, y:_root._ymouse};
}
}
onClipEvent (enterFrame) {
if (!zoom) {
return;
}
_root._xscale += dirk50/8;
_root._yscale += dirk50/8;
var pt2 = {x:pt.x, y:pt.y};
_root.localToGlobal(pt2);
_root._x -= (pt2.x-pt.x);
_root._y -= (pt2.y-pt.y);
k++;
if (k == 15) {//change here…
zoom = false;
k = 0;
}
}