I have the same problem with my online forms. I asked Host My Site about this. Here is my question and their answer.
MY QUESTION: Do you recommend a captcha script for my web forms? I have found a few but they require dll's to be installed on the server.
Is there anything already installed on the server which will allow me to put a captcha script on my webpage?
HOST MY SITE ANSWER: We dont have any that we recommend, as there are hundreds of them out there. I did a quick search and found these:
http://www.codeproject.com/aspnet/CaptchaImage.asp
http://sourceforge.net/projects/asp-captcha
If you have a specific one in mind we can take a look and let you know if we can install the required dlls for it. Also keep in mind you can use asp, .NET or perl on your server so any captcha in those languages should work fine. If you have any questions please let us know.
UPDATE:
HOST MY SITE ANSWER:We would prefer that you use the .NET version from codeproject.com as opposed to the OpenSource "ASP-Captcha" scripts.
As it is open-source software we will not be able to obtain any type of support and we cannot really vouch for the security and reliability of the DLLs it would require.
