function coms_toggle() {
 var node = document.getElementById('practitioner_fields');
 var radio = document.coms_registration_form.student_or_practitioner;
 node.style.display = radio[0].checked ? 'block' : 'none';
 node = document.getElementById('student_fields');
 node.style.display = radio[1].checked ? 'block' : 'none';
}