how to reconstruct vertical and horizontal sub-band using indwt.

I have read the help indwt but I would not understand how reconstruct the vertical and horizontal sub-band. Also, in the example, they using 'aa' to reconstruct approx. sub-band but for detail, they only use 'd'. we have 3 different detail sub-bands, which one does it refer to?

Help

Thanks

[Subash Mahanta]

I think 'd' refers to all the detail subbands, but I am not getting how to reconstruct the whole output image after processing the approximate and detail subbands.