can you provide more detail on the nature of the problem.
just saying:
captcha not want work and I don't know why
is not helpfull, there are to many possibilities of what that could mean for me to be able to help.
how is it not working?
when you try to visit your page in the browser, describe how the form is behaving.
describe how this differs from what you are expecting.
Please bear in mind the following:
The quality of the answer i can give is directly related to the quality of the question asked