Question on Captcha module on Drupal 7

Question

PHP

Situation: There is a feedback form, it opens in a modal window. When submitting the form, if the captcha is not entered correctly, then there is a redirection to the page created by Drupal - I do not need this.
Question: How to check the correctness of captcha input even before submitting the form and display a message about incorrect captcha input in the form itself.
Please tell me the algorithm of actions or at least how to get the results of captcha input before submitting the form.

Answer 1

Hello. Thank you very much for responding!!! Unfortunately, I'm still a noob in such matters. Can you please describe in more detail the algorithm of actions.

Answer 2

Display your form in a Ctools modal window.