Form Validation - Modify Second Parameter

[eluser]jamgood96[/eluser]
[quote author="Aken" date="1327970457"]Passing a parameter value works fine in CI 2.1. What version of CodeIgniter are you using? Is your callback function set up appropriately?

Note that in your example you are calling the "valid_name" callback, but have shown code for a "valid_address" callback function.[/quote]

Sorry, that's a typo there. Should be callback_valid_address.

I'm running CI 2.1. I know passing a parameter works fine, but I'm unable to modify it. Is this due to variable scope?