protected void RadListBoxSource_OnTransferred(object sender, RadListBoxTransferredEventArgs e) { if (ddlBranches.SelectedValue == "0") { ShowErrorMessage("Please select a branch from the dropdown."); return; } var itemIds = new List <int>(); foreach (var radListBoxItem in e.Items) { itemIds.Add(int.Parse(radListBoxItem.Value)); } foreach (var itemId in itemIds) { var result = ProductOperations.AssignAProductToAStore(int.Parse(ddlBranches.SelectedValue), itemId); if (!result.IsSuccess) { ShowErrorMessage("A problem occured while assigning one or more of the products."); } } }