Don't show captcha after successfully entering the first time

If a user successfully enters the captchpa, but forgets to fill in another required field, when they are returned to the yii-user registration form they have to fill in a new captchpa again. How can I adjust CCaptchaAction or the Widget itself to not require a captcha the second time? Thanks!

Usually second time even if capthe was entered correctly captcha should be asked again. Should’t it?

I’ve already seen sites/scripts where it isn’t asked again. phpBB 3 should be one of them.

I don’t see why. The person has validated they are “human” or at least that they can successfully enter a captcha. Why make them go through the trouble a second time?

I’ve implemented a hack, by creating my own MyCaptchaAction class that extends CCaptchaAction and saves a session variable in the validate method, but I doubt this is the correct way. If anyone has any suggestions on how to implement this correctly, I’d appreciate it.