inline-validation.js

// if an invalid form field has been made valid,
// remove the shouty error highlighting - if a valid
// required field has been made invalid, start shouting

$('input, textarea, select').on('change', function(){
    var $input     = $(this);
    var isRequired = $input.parents('.gfield').is('.gfield_contains_required');
    var isValid    = $input.is(':valid');

    if ( isRequired && isValid ) {
        $input.parents('.gfield').removeClass('gfield_error');
        $input.parent().next('.validation_message').slideUp();
    }

}).blur(function(){
    var $input     = $(this);
    var isRequired = $input.parents('.gfield').is('.gfield_contains_required');
    var isInValid  = $input.is(':invalid');
    var isEmpty    = $input.val() === '';

    if ( isRequired && ( isInValid || isEmpty ) ) {
        $input.parents('.gfield').addClass('gfield_error');
        $input.parent().next('.validation_message').slideDown();
    }
});