You are legally allowed to deduct certain expenses even if you are not a professional gambler. Please check with a good gambling tax professional, as I do my taxes a different way as a full time player, and more of my expenses are deductible.
BTW, Wisconsin was listed as one of the states that specifically prohibits online gambling. So please be careful dealing with your state taxes. However, you do still need to report your winnings.
http://www.gambling-law-us.com/State-Laws/
http://www.gambling-law-us.com/State-Law-Summary/
If you are only withdrawing occasionally off the net it is possible you could make a case that the year was one long session and your withdrawals were your only wins.
It seems that IRS is happy enough to have gamblers pay taxes that they are not totally crazy about going after to the full extent of the unfair rules built in the tax system.