Dynamically resizing/limiting width of a movieclip

1

I have some rectangles inside a movieclip. All movieclips are created by actionscript. I want to limit the size of the movieclip on top right corner when user starts drag.

this.holder_mc.onEnterFrame = function() {
	this.holder_mc.rectangle_6._xscale = this.holder_mc._xscale-260;
	trace(holder_mc.rectangle_6._xscale);
};

This code doesn’t work (xscale is constant). I will also need to resize the movieclip on the top left corner.