Help required adding 2 square adsense units in postbits.

[David_R]

I want to add 2 square box adsense units in my postbits.

1st adsense unit on left side of 1st post
and
2nd adsense unit on right side of 2nd post.

I am able to add first unit properly, but cannot understand how to add the second unit.
Any help is apprecaited.