private void LoadProductTypeCB() { Product product = new Product(); string display = "ProductName"; string value = "ProductID"; productCB1.DataSource = product.GetAllProductQuery(); productCB1.DisplayMember = display; productCB1.ValueMember = value; productCB2.DataSource = product.GetAllProductQuery(); productCB2.DisplayMember = display; productCB2.ValueMember = value; productCB3.DataSource = product.GetAllProductQuery(); productCB3.DisplayMember = display; productCB3.ValueMember = value; productCB4.DataSource = product.GetAllProductQuery(); productCB4.DisplayMember = display; productCB4.ValueMember = value; }