I'll try to be more specific, I want a link in the header of the pages which says; show prices in: EURO | USD. The prices are shown in EURO by default but if a visitor/customer prefers to use USD he may choose the "USD" and then the page reload and show prices in USD instead of EURO. I also just want to have one coloumn in the database products table for price and that would be in EURO, when showing USD it will be calculated from the price in EURO * exchange rate for USD.