Situations occur every now and then when you need an undo button. Such as when I am entering in readings, and hit the wrong key, or forget to hit the F4 key, then I am typing in an existing reading spot but it wiped out the existing reading for the new one to be typed on over it. But that was a mistake. It would be nice to hit an undo button to bring the old reading back, then I could hit my F4 for the new row with my new reading. There are other instances when in the information tab, I hit new and now it made a duplicate test station but I didn’t mean to for that test station. Now I have to use the delete which will still show the unnecessary duplicate I made by mistake. I know the is a filter for deleted but I like deleted to show for other situations and knowledge.  These are just a couple of situations for an UNDO button. The first example worse for losing a historical compliance reading that the commission can compare with their records and see a discrepancy if you fudge a reading back in after wiping it out accidently.