Do you know the Martingale strategy?
If not, have a look at http://de.wikipedia.org/wiki/Roulette_%28Gl%C3%BCcksspiel%29 (german) or http://en.wikipedia.org/wiki/Roulette (english).

If you still believe that this strategy could work, try out this small simulation software (in german, sorry, but therefor it's free of charge and you don't have to bet real money ;-)).

The simulation sets on a single change (red) and doubles it's bet on every lost round. Without a table limit and with unlimited money this strategy would work! But believe Albert Einstein who is reputed to have stated, "You cannot beat a roulette table unless you steal money from it.".