function Calculator() {
}

Calculator.CANS_PER_YEAR = 299;
Calculator.GHG_VIRGIN = 9;
Calculator.ENERGY_VIRGIN = 140;
Calculator.GHG_PERCAR_PERYEAR = 5.46;
Calculator.END_TO_END = 13167;
Calculator.NYC_LA = 3944;
Calculator.CAN_VALUE_LOOSE = 0.75;
Calculator.CAN_VALUE_BALED = 0.95;
Calculator.SMELTER = 240000;
Calculator.WATER_CONSUMPTION = 5;
Calculator.MBTU = 5.8;



Calculator.Calculate = function(name) {
    var theForm = document.forms[0];
    var population = Number(theForm.txtPopulation.value.replace(/,/g, ""));
    
    
    if(population != null && population != "" && !isNaN(population)) {
        var valCansRecycled;
        valCansRecycled = population * Calculator.CANS_PER_YEAR;
        lblCansRecylcled.innerHTML = Calculator.AddCommas(valCansRecycled);        
        
        var valWeightRecycled;
        valWeightRecycled = valCansRecycled / 34.21;
        valWeightRecycled = Math.round(valWeightRecycled);        
        lblWeightRecycled.innerHTML = Calculator.AddCommas(valWeightRecycled) + ' LBS';
        
        var valGHGCO2;
        valGHGCO2 = Calculator.GHG_VIRGIN * (valWeightRecycled / 2200);
        valGHGCO2 = Math.round(valGHGCO2);        
        lblGHCCO2.innerHTML = Calculator.AddCommas(valGHGCO2) + ' Metric Tons';
        
        var valEnergySaved;
        valEnergySaved = (valWeightRecycled / 2200) * Calculator.ENERGY_VIRGIN;
        valEnergySaved = Math.round(valEnergySaved);        
        lblEnergySaved.innerHTML = Calculator.AddCommas(valEnergySaved) + ' MBTUs';
        
        var valCrudeOil;
        valCrudeOil = valEnergySaved / Calculator.MBTU;
        valCrudeOil = Math.round(valCrudeOil);
        lblCrudeOil.innerHTML = Calculator.AddCommas(valCrudeOil) + ' Barrels';
    
        var valGHCCars;
        valGHCCars = valGHGCO2 / Calculator.GHG_PERCAR_PERYEAR;
        valGHCCars = Math.round(valGHCCars);
        lblGHCCards.innerHTML = Calculator.AddCommas(valGHCCars) + ' Cars';
        
        var valEndToEnd;
        valEndToEnd = valCansRecycled / Calculator.END_TO_END;
        valEndToEnd = Math.round(valEndToEnd);
        lblEndToEnd.innerHTML = Calculator.AddCommas(valEndToEnd) + ' Miles';
    
//        var valNYCLA;
//        valNYCLA = (valEndToEnd / Calculator.NYC_LA) / 1000;
//        valNYCLA = Math.round(valNYCLA);
//        lblNYCLA.innerHTML = Calculator.AddCommas(valNYCLA) + ' Trips';
        
        var valAlumnValue;
        valAlumnValue = valWeightRecycled * Calculator.CAN_VALUE_LOOSE;
        valAlumnValue = Math.round(valAlumnValue);
        lblAlumnValue.innerHTML = '$' + Calculator.AddCommas(valAlumnValue);
    
//        var valSmelters;
//        valSmelters = ((valWeightRecycled / 2200) * 1.1) / Calculator.SMELTER;
//        valSmelters = Math.round(valSmelters);
//        lblSmelters.innerHTML = Calculator.AddCommas(valSmelters);
    
        var valWater;
        valWater = ((valWeightRecycled / 2200) * 1.1) * Calculator.WATER_CONSUMPTION;
        valWater = Math.round(valWater);
        lblWater.innerHTML = Calculator.AddCommas(valWater) + ' Cubic Meters';
    }
    else {
        alert("Enter number of people");
        theForm.txtPopulation.focus();
    }
    
    return false;
}


Calculator.CalculateValue = function(number) {
    document.forms[0].txtPopulation.value = number;
    Calculator.Calculate();
}


Calculator.AddCommas = function(string) {
	string += '';
	x = string.split('.');
	x1 = x[0];
	x2 = x.length > 1 ? '.' + x[1] : '';
	var rgx = /(\d+)(\d{3})/;
	while (rgx.test(x1)) {
		x1 = x1.replace(rgx, '$1' + ',' + '$2');
	}
	return x1 + x2;
}