Anti-Robot Validation

We have a page at <[login to view URL]> which needs 2 updates: 1) Visual anti-robot validation to avoid spammers from sending us unsoliciated email; and 2) A "How did you hear about us" field on the bottom (underneath Tax ID Number) which the user should be _required_ to fill out to submit the form. The corresponding email sent to us of the form's details when submitted should also have the "how did you hear about us" info listed. Thank you.