Scale MovieClips

function scaleAtoB(a : MovieClip, b : MovieClip) : void
{
    a._xscale = trueXScale(a)/trueXScale(b._parent);
    a._yscale = trueYScale(a)/trueYScale(b._parent);
}


function trueXScale(mc : MovieClip) : Number
{
     var xscale : Number;
     while(mc != _root)
     {
          xscale *= mc._xscale;
          mc = mc._parent;
     }
}

function trueYScale(mc : MovieClip) : Number
{
     var xscale : Number;
     while(mc != _root)
     {
          xscale *= mc._xscale;
          mc = mc._parent;
     }
}