I`m a tradesman and don`t know how to calculate the Zakah due on trading items. Hawl (Zakah year) has lapsed only over some of the goods; some have been damaged and I might return them to the owner. Sometimes, I pay for goods in advance and, sometimes, by installments. I also have money in my bank account, in addition to cash and uncashed checks. Also, people owe me money; some of which are repayable and some are unrepayable. I`m also indebted and have taxes and expenses to pay. I have vehicles, such as cars, trucks and the like, real estate; some are for trade and some aren`t, and some I rent to generate income. This is in addition to my own private money, car and house and other items not set for trade. My wife has also adornment gold, in addition to gold for saving. What is the ruling of Sharia on all of this?