[TYPO3-english] Image captcha with TYPO3 form

[Web Essentials - Support (Phallin Hor)]

Dear list,

I want to implement image captcha into default TYPO3 form. I have used 
sr_freecap with my form. However, it seems not working on my website.
The extension manual here 
http://docs.typo3.org/typo3cms/extensions/sr_freecap/UsersManual/Index.html 
seems difficult for me to understand.

My website environment:
     - TYPO3 6.2.3
     - sr_freecap 2.0.8
     - GDlib works fine in installtool
     - PHP Version 5.4.13

Does anyone have any idea or other extensions that work and support with 
default form in TYPO3 6.3.2? Thank you in advance for your help.

Best regards,
Phallin