And this is way the current situation of financial crisis living together with a growing demand for domestic currency and public bonds as in the US is unknown for the developing world, allowing the policy makers to provide liquidity to the financial system and fund the banking bailout with fiscal resources avoiding a twin crisis.
We are complementing this by raising interest rates in the interbank market and on repo instruments. Of course open market exchange rates are difficult to control and no central bank can guarantee to move the exchange rate in the direction it wants.