I have not managed to find much on this so any info would be appreciated. I just need to make sure the script runs to all my users regardless of what version of reader they are using.
Is this possible?
On the other hand, with the exception of "security" annoyances, old code (developed in Acrobat 4 or so) usually still works in Acrobat 10. This means, that you can program for a specific Acrobat version, and it should be fine with several newer versions as well. If not sure, check the documentation (mentioned by George) and try it out.