(function ($) {
var extra_settings = function () {
var custom_size_panel = $('#wp_rp_custom_thumb_sizes_settings');
if ($('#wp_rp_custom_size_thumbnail_enabled:checked').length) {
custom_size_panel.show();
} else {
custom_size_panel.hide();
}
$('#wp_rp_custom_size_thumbnail_enabled').click(function() {
custom_size_panel.toggle(this.checked);
});
}
$(extra_settings);
}(jQuery));