i would like to use vtiger for stock evidence for our rented products. When we rent our product, I write new invoice to selected customer with selected products. Under invoice in vtiger, i added new status returned, when products are returned to us, I would open the same invoice regarding that products, change status to returned and save the invoice. Products should be added back to qty. in stock, on the same state like before writing that invoice. From closed invoice(with status returned) must be seen what products was rented, how many and when was invoice closed for Evidence. I believe this can be done with workflow in vtiger, but dont know how to do it.