This crap sounds dangerous. I 'd pretty much put on the max position possible on my entry and peuk out if it didn't work out, which would be astronomically improbable.
Here's the link: http://www.interactivebrokers.com/en/trading/marginRequirements/margin_amer.php?ib_entity=llc
jaronimo and the other guy, you got it all wrong. everyone knows that the smart money is on the green numbers on roulette!
Take out an extra mortgage on your house, use that equity to increase your position size for your 99% profitable trade, then pay it off the next day with your profit. Or try to get some other loan, it will be for such a short period you won't have to worry about interest! How about getting a bunch of credit cards and getting a cash advance.