1. Copy captchaCode.php and captchaImage.php file and paste it in your project folder.
2. Open home.php. Include all the codes mentioned in STEP 1 at the top of your php file in which the form is present.
3. In your form just copy the image link as presented in  STEP 2 and paste it inside the form.
4. To verify the submitted captcha value by the user, verify it with $code.  $code contains the correct value of the captcha.