Testing is an important part of interactivity. If one action is chosen, then something must happen. If another action is chosen
then something else happens. In this exercise we see a practical example that removes form field hints when the user clicks
into them. It’s important to note that only the hints are removed, allowing the user to click back into the fields to make corrections.
This is the proper behavior, but we’ve seen sites that remove the user’s text as well, requiring them to re-type the
whole entry when they try to fix a mistake.
