var int = self.setInterval("DisplaySavings()", 1000);

function SavingsCalc() {

    var dateRef = Date.UTC(2007, 0, 1);

    var dateNow = new Date();
    dateNow = dateNow.getTime();

    var dateDiff = ((dateNow / 60000) - (dateRef / 60000));
    var minutesDiff = dateDiff; 						//  60000 milliseconds in a minute.
    var hoursDiff = (minutesDiff / 60); 				//	60 minutes in a hour.
    var daysDiff = (hoursDiff / 24);
    var yearsDiff = (daysDiff / 365);

    var numSquareFeet = Number(1000000000); 			//  1 Million SQ feet
    var numWattsPerSqFt = Number(1.2); 				//	1.2 watts per SQ foot
    var numHoursOffPerYear = Number(2800); 			//  Hours of OFF per year
    var numCentsPerKWh = Number(0.12); 				//  Average cost per kW h is $0.12
    var numKiloWattHours = Number(0); 				//  Number of kiloWatt hours used

    var numKiloWattHours = (((numSquareFeet * numWattsPerSqFt) / 1000) * numHoursOffPerYear);
    var numTotalSavings = (numKiloWattHours * numCentsPerKWh) * yearsDiff;

    numTotalSavings = numTotalSavings.toFixed(2); 	// Set precision at two decimal points.

    var strTotalSavings = numTotalSavings.toString();


    var end = Number(strTotalSavings.length); // number of characters in the String
    var decimalAndAfter = strTotalSavings.substr((end - 3), end); // the decimal point and all the numbers after it

    var hundreds = strTotalSavings.substr((end - 6), 3);
    var thousands = strTotalSavings.substr((end - 9), 3);
    var millions = strTotalSavings.substr((end - 12), 3);
    var billions = strTotalSavings.substr(0, end - 12);

    strTotalSavings = "$" + billions + "," + millions + "," + thousands + "," + hundreds + decimalAndAfter;

    return (strTotalSavings);



}
function DisplaySavings() {
    if (document.getElementById('total_savings') != null) {
    document.getElementById('total_savings').innerHTML = SavingsCalc();
    }
}