how to include a css-hidden input field in forms

Question

I want to include a css-hidden input field in forms and check if the hidden field has it’s value filled out then reject the submission

Answer 1

Brief tutorial: Fighting Spam with CSS

A more comprehensive article on the subject: Stopping spambots with hashes and honeypots

Answer 2

You may try something like this:

if (isset($_POST['submit']) && strlen($_POST['hidden_field']))
{
  // proceed with submission
}
else
{
  // reject because hidden field does not contain any value.
}