I am having trouble clearing the form input upon failed validation of the form.
For example the form validation function would throw an error if there is a there is any radio button element in the form, of which there is two groups, left unchecked. If the user select the first group, but does not select for the second group, an error is thrown. I would like to know how I can clear the form input such that the previously selected radio button in group 1 is cleared.
This is being done with Drupal 7.