Problem with lines

Hi, please try this minor change:

protected void repeater1_OnItemDataBound(object sender, RepeaterItemEventArgs  e)
        {
            if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
            {
                var item = e.Item.DataItem as Model;
                if (item != null)
                {
                    var cb_app = e.Item.FindControl("cb_app") as CheckBox;
                    ...