HOW TO ADD A CAPTCHA TO A FORM ALREADY EXISTING:
**if the form uses the vforms function and posts to a confirmation, and you see NO ASP programming on the page, just rip out that form and replace it with the standard captcha form.

1. open http://asamplesite.com/blanksite/captcha and copy the following files into an INCLUDES file in your site:
   1. aspcaptcha.asp
   2. aspcaptchafunction.asp
       
2. Add the following form information to the form where you want it to appear:
   <p>
   <label>Type the characters shown in image for verification.</label><br/>
   <img src="/includes/aspcaptcha.asp" alt="" width="86" height="21" align="top" /><br>
   <input name="strCAPTCHA" type="text" id="strCAPTCHA" maxlength="8" class="form" />
   </p>
    
3. Add the following include to the top of the form include page.
   <!--#include virtual="/includes/aspcaptchafunction.asp"-->
    
4. Now, RIGHT AFTER the "if request method = post" code, look for the section where the variables are defined. add the following:
   
   strcaptcha = stringvalidate(request.form("strcaptcha"))
    
5. after the code where the variables are defined, before any other processing is done add this:
   
   if CheckCAPTCHA(strCAPTCHA) = false then
       errormessage = errormessage & "<font color='red'>You did not type in the verification info correctly.</font><br>"
   else
       <all the other programming that's already there>
   End If
    
6. Last, add the errormessage to show AT THE TOP OF THE FORM in case they didn't fill it out right. paste this code:
   
   <% if errormessage <> "" then
           response.write errormessage
           end if
   %>
    
7. Note: It is IMPERATIVE that ALL FIELDS are pre-populated on the post if you use the captcha so the visitor doesn't have to type them in again.
   
    

Note: these instructions can be found at http://asamplesite.com/blanksite/captcha

examples can be found here:
http://themouthstore.com/contactus.asp
http://freedomrxinc.com/contact.asp