Forum OpenACS Q&A: passing dynamic varialbes to error message in ad_form validation block

I'm trying to validate my form widgets but want to pass a dynamic error message in the validation block. For example, if I'm uploading an image and I'm validating the dimensions I want the inline error to say "You tried to upload an image of dimensions $x by $y and we require the dimensions to by 20 by 50". Reading through the docs, I see no way of passing the variables x and y after calling the validation procedure. I tried upleveling the vars to the stack frame where ad_form is called, but it didn't like that either.

Is there a way a good way to do this, preferably without having to mess with upleveling vars?

Thanks for the advice!
Jeff