[Drupal] How to add the catcha to the webform

1. Install captcha
2. Go to admin/user/captcha
3. Check "Add CAPTCHA administration links to forms"
4. Go to your webform node (just view it, do not edit)
5. Expand the "CAPTCHA" fieldset at the bottom of the form
6. Click "Add CAPTCHA here"
7. Add the captcha
8. Logout and see the captcha