Ratslinger, you are genius.It worked as a charm indeed!
Haha, the option button is there on purpose. I put it as I could not find another way to stretch my bottom margin, so I put a non working tiny option button. 
As for the macro, it was there forgotten, so I deleted it.
But now, how can I control if something is changed on my record before refreshing the form? The only solution is putting a macro? And if yes, is there a macro that has worked for you? And in which SubForm should I put it?
Macros are not for you - at least until you learn a great deal more. Form=Master; the other two are People & Visits. On the Master, add a button with an action of Save record. If you make changes to Master click save record before any NEW selection with refresh button. For People & Visits (not all fields on these) any changes will be saved anytime you got to a different line in the grid. No button necessary for these. You can even add new entries for these two; going to a new line saves.
If this answers your question please click on the 
(upper left area of answer).
Well, I understood your solution but my problem is the opposite… Everything that is written, even by mistake, (or maybe someone erases data by mistake) is saved automatically on the record change. So I just would like to put a reminder before the record change to remind the user that somewhere he made changes. If he did on purpose he will click Yes and jump to next record. If not, he will click No, the changes will revert and he will jump to next record. This can only done with macro?
@preks The forum is set up to ask a question and (hopefully) get an answer which satisfies the question. Then people can search for their problem and possibly find an answer to their question. If different questions are presented and answered after the initial question, it gets buried. For no other reason, please ask this as a new question. It is actually a pretty good question.
That’s what I wrote in my initial question: “Of course I want this message to appear if I do some changes, but only when that happens, else it is irritating to appear all the time.”
We found the way to make it disappear totally (by giving it the correct structure), but that’s not what I asked in my first question.
Sorry I didn’t read it that way. Let me give it a bit of thought.
No, wait… I create a new question… 
Thank you very much. Let’s close this one. You can find my next question on my profile!
@preks FYI - the message referred to in you question was actually related to a change made to the “Filter” table because the listbox had changed the value but the record was not updated yet when the refresh button was selected. Of course, when the button was moved to the correct position the message stopped. So the approach now must take on a whole different aspect. I write this only so you understand what was happening.
Oh, thank you very much. Nice to understand it. 