// JavaScript Document
function calculateSize()
	{
		var Lights=0;
		var WattPerLight=0;
		var UsageLights=0;
		var TotalWattLights=0;
		
		Lights = document.estimatorForm.Lights.value;
		WattPerLight = document.estimatorForm.WattPerLight.value;
		UsageLights = document.estimatorForm.UsageLights.value;
		TotalWattLights = Lights * WattPerLight * UsageLights;
		document.estimatorForm.TotalWattLights.value = TotalWattLights;
		
		var Fans=0;
		var WattPerFan=0;
		var UsageFans=0;
		var TotalWattFans=0;
		
		Fans = document.estimatorForm.Fans.value;
		WattPerFan = document.estimatorForm.WattPerFan.value;
		UsageFans = document.estimatorForm.UsageFans.value;
		TotalWattFans = Fans * WattPerFan * UsageFans;
		document.estimatorForm.TotalWattFans.value = TotalWattFans;
		
		var OtherUnits=0;
		var WattPerOtherUnit=0;
		var UsageOtherUnits=0;
		var TotalWattOtherUnits=0;
		
		OtherUnits = document.estimatorForm.OtherUnits.value;
		WattPerOtherUnit = document.estimatorForm.WattPerOtherUnit.value;
		UsageOtherUnits = document.estimatorForm.UsageOtherUnits.value;
		TotalWattOtherUnits = OtherUnits * WattPerOtherUnit * UsageOtherUnits;
		document.estimatorForm.TotalWattOtherUnits.value = TotalWattOtherUnits;
		
		var TotalWattDailyUsed=0;
		
		TotalWattDailyUsed = TotalWattLights + TotalWattFans + TotalWattOtherUnits;
		document.estimatorForm.TotalWattDailyUsed.value = TotalWattDailyUsed;
		
		var WattPanels=0;
		var NeedTotalPanels=0;
		var DailySunshine=0;
		
		WattPanels = document.estimatorForm.WattPanels.value;
		DailySunshine = document.estimatorForm.DailySunshine.value;
		
		NeedTotalPanels = TotalWattDailyUsed / DailySunshine / WattPanels;
		document.estimatorForm.NeedTotalPanels.value = NeedTotalPanels;
		

		if (NeedTotalPanels > 0 )
		{
			document.estimatorForm.NeedTotalPanels.value = Math.ceil(NeedTotalPanels);

		}
		
		var BatteryCapacity=0;
		var BatteryCapacityTwelveVolt=12;
		var BatteryCapacityTotalWatt=0;
		var NeedTotalBatteries=0;
		
		BatteryCapacity = document.estimatorForm.BatteryCapacity.value;
		BatteryCapacityTotalWatt = BatteryCapacityTwelveVolt * BatteryCapacity;
		NeedTotalBatteries = TotalWattDailyUsed / BatteryCapacityTotalWatt;
		
		document.estimatorForm.NeedTotalBatteries.value = NeedTotalBatteries;
		
		if (NeedTotalBatteries > 0 )
		{
			document.estimatorForm.NeedTotalBatteries.value = Math.ceil(NeedTotalBatteries);
		}
		
	}