Gravity Forms Conditional Required Fields Javascript

//
// setup required fields.  Variables set as:
// initial_question, followup_question
// Note: This has not been tested with Ajax enabled, so it still requires
// a check on the server side.
//

var $q8  = jQuery('li#field_2_16'), $q9  = jQuery('li#field_2_25'),
    $q10 = jQuery('li#field_2_18'), $q11 = jQuery('li#field_2_30'),
    $q12 = jQuery('li#field_2_20'), $q13 = jQuery('li#field_2_21'),
    $q14 = jQuery('li#field_2_22'), $q15 = jQuery('li#field_2_23'),
    requiredAsterisk = '<span class="gfield_required">*</span>';

//
// check for change in field, and mark updateField required if triggerChoice is checked
//
function checkField(triggerChoice, $updateField) {
    // check to see if the triggerChoice input is checked
    if ( jQuery(triggerChoice).attr("checked") === 'checked' ) { // is checked
        // mark the updateField as required if it isn't already
        if ( $updateField.find("span.gfield_required").length == 0 ) {
            $updateField.find("label").eq(0).append(requiredAsterisk);
        }
    }
    else { // not checked
        // we remove the required asterisk since the trigger is not set
        $updateField.find("span.gfield_required").remove();
    }
    return;
}

//
// this looks for a change on the initial question's input field
// once its found, it calls the checkField function.  It takes two fields:
//
// triggerChoice : the selector for the input field of the option/choice in
// the initial question that makes the followup question now required
//
// $updateField : This is the field will get updated and set as required if triggerChoice
// is checked.
//

$q8.find('input').on('change', function() { checkField('input#choice_16_1', $q9); } );
$q10.find('input').on('change', function() { checkField('input#choice_18_1', $q11); } );
$q12.find('input').on('change', function() { checkField('input#choice_20_4', $q13); } );
$q14.find('input').on('change', function() { checkField('input#choice_22_4', $q15); } );

//
// Since the fields might still be required after an attempted page submit, we do a check  once the page
// has loaded, these checkField calls are identical to the ones in the four lines above.
//
checkField('input#choice_16_1', $q9);
checkField('input#choice_18_1', $q11);
checkField('input#choice_20_4', $q13);
checkField('input#choice_22_4', $q15);