private void foodcategoryButton_MouseClick(object sender, MouseEventArgs e)
        {
            //when the button is clicked - need to get the category id of that name
            String foodCategoryBtnID = txtFCBtnCategoryID.Text;
            //MessageBox.Show(foodCategoryBtnID + " Buttton clicked");

            RestaurantPOS resPos = RestaurantPOS.getInstance();

            resPos.filterFoodCards(foodCategoryBtnID);
        }
        private void ItemCategoryButton_Click(object sender, EventArgs e)
        {
            String        foodCategoryBtnID = txtICBtnCategoryID.Text;
            KitchenPOS    kpos = KitchenPOS.getInstance();
            RestaurantPOS rpos = RestaurantPOS.getInstance();

            if (ItemButtonID.StartsWith("KIc"))
            {
                kpos.filterFoodCards(foodCategoryBtnID);
            }
            else if (ItemButtonID.StartsWith("RPc"))
            {
                rpos.filterFoodCards(foodCategoryBtnID);
            }
        }