Actionscript 3 :: MovieClip Resizes But Its Children's Height And Width Are Not Changed?

Changing the width and height of the parent MovieClip does not bring change in the width and height of the inner MovieClip. The parent MovieClip is placed at Stage and is resized manually. When I assign the dimension of the parent MovieClip to the inner MovieClip through code, the parent MovieClip dimension is changed. I want both MovieClip to be of same width and height at runtime. However, parent MovieClip dimension is changed at design time by me.

Example:There are two MovieClip, one inside another. Now parent MovieClip is placed at Stage at design time and its dimension is (50,50) and the child MovieClip which is inside the parent MovieClip has also same dimensions (50,50). Now, I manually change the parent MovieClip dimension by pressing Q and stretching it with mouse, the dimension of the parent MovieClip is now (100,150) or whatever I like. Now double-click on parent MovieClip and check that inner MovieClip dimension remains same i.e. (50,50)Now in AS3 code, I change the width and height of inner MovieClip like this:

saveheight = parentmc.height;
savewidth = parentmc.width;

now I change the child MovieClip according to the dimensions of the parent MovieClip like this:

parentmc.inner_mc.width = parentmc.width;
parentmc.inner_mc.height = parentmc.height;

but this brings change in parentmc also so I reassign value to parentmc like this:

parentmc.height = saveheight;
parentmc.width = savewidth;

In above case, parentmc and inne_rmc dimension should be same i.e (100 ,150). With swapping the values as above, I get parentmc and inner_mc to be of same dimension, but object size is never (100, 150), I have checked it with pixel-perfect air app.