Just playing around at the moment, but am curious to know how losses work.  
So as an example, you buy a stock for $10.  A few hours later, the calue of the stock has gone up, you sell it and make $5 (and get back what you spent on it for a $5 profit, $15 'deposit' back into your account).
The other way, you buy a stock for $10.  The value goes down.  How can you lose more than $10?  You're not paying someone to take the stock off your hands - someone else is buying it.  
On paper, i 'spent' $33 buying 100 contracts in Norway.  The value plummeted and now I potentially owe $98.  To whom am I paying this?  And would I get back the initial $33, making the loss more around the $65 mark?
Sorry if it's a dumb question, I just don't understand how you can lose more than what you put in.