Form Validation - Modify Second Parameter

[eluser]jamgood96[/eluser]
[quote author="Aken" date="1327971042"]What do you mean you're unable to modify it? Can you give me a code example?[/quote]

I mean I can pass the variable to the callback function, but if I want to modify it, then access it after the callback function, I'm unable to.

Let's say the variable is equal to 0 prior to being passed to the callback. I send it to the callback, the callback then changes it to 1. If after the callback, I try to access the variable, it is still equal to 0.

Make sense?