If you need to use captcha we strongly suggest outsourcing to recaptcha.net
It could not be easier. here is how to:
public_key='xxx' ### provided by recaptcha.net private_key='xxx' ### provided by recaptcha.net def index(): form=FORM(RECAPTCHA(request,public_key,private_key),INPUT(_type='submit')) if form.accepts(request.vars,session): response.flash='done!' elif form.errors.has_key('captcha'): response.flash='invalid capctha' else: response.flash='some other error in your form' return dict(form=form)
The RECAPTCHA helper works very much as the input helper but it always take (request,publickey,privatekey) and validates itself. If it does no pass validation an error message is stored in form.errors['captcha'] but not displayed. It is up to the developer to display the error as appropriate.