What are your wages being garnished for? Are they being garnished for something preceding the jail time or debts that have occurred since then? Either way, I'm not an expert but I don't believe serving time in jail absolves you from paying your debts. If you don't have the money to pay your debts and your wages are going to be garnished, you may want to talk to an attorney and look into filing for bankruptcy.
If you have more questions about wage garnishment, check out the Department of Labor (DOL) website's resources: (removed)