function calcPoundsSaved() {
	// ***************************************
	// * change these values as necessary *
	// ***************************************
	var prevPoundsSaved = 656105;	// pounds saved from 10/1/05 through 2/29/08
	var curStartDate = new Date("March 1, 2008 00:00:00");	// current period start date
	var curRate = 23.2115;			// pounds saved every 1/2 hour in current period

	// other variables
	var today = new Date();
	var oneHalfHour = 1000 * 60 * 30;	// milliseconds in one 1/2 hour
	
	// curPeriod is the time between the start date and right now; the number of
	// milliseconds in the current period is determined by using getTime(), which
	// returns in the number of milliseconds since 1/1/1970;
	var curPeriod = today.getTime() - curStartDate.getTime();
	
	// curOffset is the adjustment for Daylight Savings Time; getTimezoneOffset()
	// returns the difference in minutes between Greenwich Mean Time and local time;
	// the number of offset 1/2 hours is determined by dividing by 30
	var curOffset = (today.getTimezoneOffset() - curStartDate.getTimezoneOffset()) / 30;

	// determine number of full 1/2 hours in current period
	var curHalfHours = Math.floor((curPeriod / oneHalfHour) - curOffset);
	
	// calculate, format and write whole pounds saved
	var poundsSaved = Math.round(prevPoundsSaved + (curHalfHours * curRate));
	poundsSaved = poundsSaved.toString();
	var regExp = /(-?\d+)(\d{3})/;
	while(regExp.test(poundsSaved)) {
		poundsSaved = poundsSaved.replace(regExp, "$1,$2");
	}
	document.write(poundsSaved);
}