Hi there,
Depends what it is. Some functions/features were either a) non-existent in previous versions or b) had a different syntax, or less options associated with it.
You could either 1) try your code or 2) post it and see if anybody can see anything they know wouldn't work in prior versions. It is always best, when using multiple versions, to code from the oldest version forward, this way you can ensure forward/backwards compatability.
And it's not a stupid question.
