Completely agree with reproducibility of research. Would be great to further improve such algorithms using data collected from the public--selection issues and inaccuracies aside.
The algorithm is in the appendix of the article the tool links to.
Input fields are limited via javascript so may not have worked if you have it disabled. You're right we should do it server side as well.
Thanks for the feedback.
I should point out that I didn't develop it. It was created by the people at Symcat. They are certainly open to any feedback, here's the blog post: http://blog.symcat.com/post/67337436520/cv-risk-calculator-r...
Could you provide a link to the code for the algorithm you're implementing? (If I were a better developer, I'd probably be able to find it through your source code, but alas...)
Also, I'd suggest you limit the input fields to numbers within the allowable range. Or, at the very least, to positive numbers.