As soon as you change the layout name, all of the scripts and buttons that use Go to Layout and have a definite layout selected will change. If you use the Layout Name by Calculation option - those don't change.
It is probably easier to make two copies of the original layout, modify one of them and then copy and paste the elements on the layout onto the original, replacing them. I suggest making two copies so that you have one as a working copy and another as a backup. You'd be able to delete the "working copy" once you're done with the modifications.
OK, so the moment I change the name of the old layout to "MyLayoutOld", the references would be broken, even though the final result would NOT be a name change--that is, I WOULD have a new layout with the "MyLayout" name...
You can change layout names all day long, and your scripts will continue to point to the original layout. The various script steps and calculation elements work based on the internal ID. It will not break any references to the old layout, and it will not cause your scripts to redirect to a new layout that's named the same as the old one.
The only exception, as David mentioned, is anything that causes the layout name to be calculated via a calculation dialog where you use a text calculation to have FileMaker parse out the name explicitly.
The scripts and buttons use the internal ID.
So no. If you change the layout name, and you are just using the basic Go to Layout script step, NOTHING changes.
You land on the same (old) layout that now has a different name.
If your scripts (or buttons) use go to Layout Name by Calculation then you will land on the new layout.
OK, I believe I've got it. DavidZakary, I think I misread your reply--my apologies.
So when I change a layout name, the scripts (using the Go To Layout step) that point to it will "change" to the new layout name. That is, they'd be pointing to "MyLayoutOld", because FM is looking at the internal ID--let's say #5. Same for the buttons using "Go To Layout".
To get them to redirect to my new layout--now named "MyLayout", but the name is irrelevant because FM sees this as Internal ID #150--I'd have to find all those references/steps and manually "repoint" them.
I like the idea of cutting and pasting into my existing layout!
I have been reading with interest the concept of using calculations--and script parameters--for navigation. Unfortunately we have a legacy database built with much older versions of FM that uses a lot of the Go To script steps, so we're a long way from ideal.