Thanks to the help from the forum, I was able to write a script that can automatically check values for multiple records in a checkbox set. See:

http://www.fmforums.com/forum/showtopic.php?tid/199116

Now I'd like to know if it's possible to do the same for unchecking values.

Anyone?

To unckeck values, you remove the value form the string (instead of adding it).

This could be done with the Substitute function, but if you have FMP Advanced there is probably a custom function that will do the same thing only more easily.

See here for a method to toggle a value on/off:

http://fmforums.com/forum/showtopic.php?tid/191281/

Note: mind the trailing (or not) CR.

if you have advanced, try Matt Petrowsky's custom function, AddRemove CF

I'm sorry, this doesn't seem to work.

The idea is:

field1 = 1,2,3,4... (each checked or unchecked)

By clicking a button I want to deselect all 3's.

Multiple values in a checkbox field are always separated by carriage returns, not commas or anything else. (You may have written the commas only for display, but it's misleading.)

The ideas posted will work.

It took me a while, and I had to change a few things in the script, but now I understand. Thank you!