Subsitute out This Script;

if(state=="down"){
this.mover._xscale+=5;
this.mover._yscale+=5;
xgrow=(((this.mover._xscale*0.01)*500)-500)/2;
ygrow=(((this.mover._yscale*0.01)*500)-500)/2;
scale=((this.mover._xscale*0.01)*500)-500;
if(_root._xmouse>250){
this.mover._x-=xgrow/4;
}
else if(_root._xmouse<250){
this.mover._x+=xgrow/4;
}
if(_root._ymouse>150){
this.mover._y-=ygrow/4;
}
else if(_root._ymouse<150){
this.mover_y+=ygrow/4;
}
}

http://jsnider.0catch.com/mag4.html

It could be taken further but by adding or subtracting out the Radius but that should do.