Use CAPTCHA module on a custom HTML form? (no use of Drupal Form API) Is it possible to use the CAPTCHA module on a custom HTML form created in a content page of a Drupal 7 site?  I am not using the Drupal Form API or webform modules.  The form has the following code:    

&lt;form id="signup_form" action="[form action]" method="post" enctype="application/x-www-form-urlencoded"&gt;
&lt;div&gt;
&lt;input id="firstName" tabindex="1" type="text" name="firstName" placeholder="First Name" value="" required /&gt;
&lt;label for="firstName"&gt;First Name* &lt;/label&gt;
&lt;/div&gt;

&lt;div&gt;
&lt;input id="lastName" tabindex="2" type="text" name="lastName" placeholder="Last Name" value="" required /&gt;
&lt;label for="lastName"&gt;Last Name* &lt;/label&gt; 
&lt;/div&gt;

&lt;div&gt; 
&lt;input id="email" tabindex="3" type="text" name="email" placeholder="Email" /&gt;
&lt;label for="email"&gt;Email* &lt;/label&gt;
&lt;/div&gt;

&lt;input type="hidden" name="form_id" value="signup_form" /&gt;
&lt;div&gt;
&lt;input id="btn-submit" tabindex="6" class="submit" type="submit" name="submitButton" value="SIGN UP" /&gt;
&lt;/div&gt;
&lt;/form&gt;


I'm trying to have reCAPTCHA displayed at the bottom of the page when there has been an X number of form submissions from the same IP address in a given amount of time.   I was hoping CAPTCHA After could work for my custom form -- I tested it on our site's Admin Login page (/user) and it worked great, of course.  

I can't seem to get any CAPTCHA displaying on my custom HTML form page.  In the General Settings, I selected "Add CAPTCHA administration links to forms" and a drop-down with "CAPTCHA: CHALLENGE "RECAPTCHA" ENABLED" displayed in the content page where the form is coded.

Since the HTML id has nothing to do with $form_id... I referenced this Drupal Stack Exchange page, and haven't been able to generate the form ID...I'm wondering maybe my custom HTML form doesn't have a $form_id because it doesn't use any drupal form modules?  If that's the case, then I probably can't use the CAPTCHA module.  Could someone please confirm?

Perhaps I can't use any Drupal modules and may need to:


grab the user's IP address from the header via PHP:

$ip_address = $_SERVER["REMOTE_ADDR"];
store this IP address in some sort of database and add a timestamp
delete any IP address entities in that are over an hour old
count the number of data store entities via loop and if the same IP address appears a certain # of times in a given amount of time, then display reCAPTCHA 


Any guidance would be great.  Thank you!
I'm wondering maybe my custom HTML form doesn't have a $form_id because it doesn't use any drupal form modules? If that's the case, then I probably can't use the CAPTCHA module. Could someone please confirm?


Correct - the Captcha module has been written exclusively for integration with forms built by the core form API. Without a lot of changes, it's not possible to use any of its functionality on a form that hasn't been built by Drupal.