From 1 December 2008 the rate of VAT is being cut to 15%. The cut will last for 13 months until the end of 2009. It means a £1,000 Christmas shopping spree would cost a mere £25 less. But this calculator aims to show how much you would save over the term of the reduction - whether you maintain your spending or spend for Britain. =4; return (b_ok); } function getPeriod(periodType){ period = 13; //months if (periodType == "week") return (52/12) * period; if (periodType == "month") return period; if (periodType == "year") return period/12; return new Number(period); } function getWeeklyReduced(){ p = getPeriod("week"); var food_bill = new Number(document.f1.food_bill.value) * p; var weekly = new Number(0); weekly = food_bill; return weekly; } function getWeekly(){ p = getPeriod("week"); var alcoholic_drinks = new Number(document.f1.alcoholic_drinks.value) * p; var takeaways = new Number(document.f1.takeaways.value) * p ; var week