gistfile1.js

<!-- Siding Calculator -->

		<!-- Begin -->

			function getSidingROI(form) {

				sqft=eval(form.sqft.value)

				bill=eval(form.bill.value)

				homeValue=eval(form.homeValue.value)



				<!-- Assumptions-->

				energyDecrease=0.03

				energyIncrease=0.05

				sidingPercent=0.85

				

				estimatedJobCost=5.5*sqft

				homeValueInc=estimatedJobCost*sidingPercent

				homeValueTotal=homeValue+homeValueInc

				firstSavings=(energyDecrease*bill*12)+homeValueInc



				y1 =energyDecrease*bill

				y2 =y1*(1+energyIncrease)

				y3 =y2*(1+energyIncrease)

				y4 =y3*(1+energyIncrease)

				y5 =y4*(1+energyIncrease)

				y6 =y5*(1+energyIncrease)

				y7 =y6*(1+energyIncrease)

				y8 =y7*(1+energyIncrease)

				y9 =y8*(1+energyIncrease)

				y10=y9*(1+energyIncrease)

				

				

				avgtmp=(y1+y2+y3+y4+y5)

				fifthSavings=(12*avgtmp)+homeValueInc

				tenthSavings=12*(avgtmp+y6+y7+y8+y9+y10)+homeValueInc

		

				fiveROI=100*(fifthSavings/estimatedJobCost)

				tenROI=100*(tenthSavings/estimatedJobCost)



				form.homeValueInc.value = homeValueInc | 0

				form.homeValueTotal.value = homeValueTotal | 0

				form.firstSavings.value = firstSavings | 0

				form.fifthSavings.value = fifthSavings | 0

				form.tenthSavings.value = tenthSavings | 0

				form.fiveROI.value = fiveROI | 0

				form.tenROI.value = tenROI | 0
				
				//form.msg.value = "* Job cost will vary depending upon Hardie type, size, etc."

			}

		<!-- End -->

    

    <!-- windows calculator -->

		<!-- Begin -->

			function getWindowsROI(form) {

				wndws=eval(form.wndws.value)

				bill=eval(form.bill.value)



				<!-- Assumptions-->

				energyIncrease=0.05

				energyDecrease=0.30

				

				estimatedJobCost=585*wndws

				

				tmp = estimatedJobCost-(110*wndws)

				if (tmp > 5000) {

					energyTaxCredit=5000*0.30

				} else {

					energyTaxCredit=tmp*0.30

				}



				firstSavings = (energyDecrease*bill*12)+energyTaxCredit

				

				year11=energyDecrease*bill

				year12=12*year11

				year13=energyTaxCredit+year12

				year21=year11*(1+energyIncrease)

				year22=12*year21

				year23=year22+year13

				year31=year21*(1+energyIncrease)

				year32=12*year31

				year33=year32+year23

				year41=year31*(1+energyIncrease)

				year42=12*year41

				year43=year42+year33

				year51=year41*(1+energyIncrease)

				year52=12*year51

				year53=year52+year43

				year61=year51*(1+energyIncrease)

				year62=12*year61

				year63=year62+year53

				year71=year61*(1+energyIncrease)

				year72=12*year71

				year73=year72+year63

				year81=year71*(1+energyIncrease)

				year82=12*year81

				year83=year82+year73

				year91=year81*(1+energyIncrease)

				year92=12*year91

				year93=year92+year83

				year101=year91*(1+energyIncrease)

				year102=12*year101

				year103=year102+year93

				

				avgtmp=(year11+year21+year31+year41+year51)

				

				fiveYearAvg1=avgtmp/5

				fiveYearAvg2=12*fiveYearAvg1

				fiveYearAvg2=fiveYearAvg2+year103

				

				fifthSavings=(12*avgtmp)+energyTaxCredit

				tenthSavings=12*(avgtmp+year61+year71+year81+year91+year101)+energyTaxCredit

				fiveROI=100*(fifthSavings/estimatedJobCost)

				tenROI=100*(tenthSavings/estimatedJobCost)

				payBackYears=100*(5/fiveROI)

				

				form.energyTaxCredit.value = energyTaxCredit | 0

				form.firstSavings.value = firstSavings | 0

				form.fifthSavings.value = fifthSavings | 0

				form.tenthSavings.value = tenthSavings | 0

				form.fiveROI.value = fiveROI | 0

				form.tenROI.value = tenROI | 0

				form.payBackYears.value = payBackYears.toFixed(1)
				
				//form.msg.value = "* Job cost will vary depending upon type of windows selected, size, etc. ** Energy Tax Credit expires at the end of 2010."

			}

		<!-- End -->