Builds a simple form to test duplicate HTML IDs.
function form_test_html_id($form, &$form_state) {
$form['name'] = array(
'#type' => 'textfield',
'#title' => 'name',
'#required' => TRUE,
);
$form['submit'] = array(
'#type' => 'submit',
'#value' => 'Save',
);
return $form;
}