Macro to color bacground of the cell and log time if cells content changed

Hi Everyone! I have an excel file which is used by a few people. This file is a share file which is used monthly. The users change their previous comments, or do nothing. I would like to have a macro which in case a cells old value is changed (old comments deleted and added new ones, or suplementary comments added to the old ones) it automatically colors the background of the cell to be red. And it also adds the time and date when the change was made in the same row, column "H".
I hope I was understandable.

Thank you in advance for your help.

Please, could someone help me??
Thank you!

Is this really so hard that no one calp me?????

Dear Roy!

This is PERFECT!! ) Thanks a lot.
However there is one small thing though... The function Now() should be but allways changed cells row but the column "H".

Can you help me on this one?

Thank you in advance!