// Description: HERS Calculator JavaScript Program for Title24EnergyCalcs
// Date: January 29, 2006

function hers_calculate() {
	var intTotal = 0;
	var intAddresses = document.hers_calculator.address_count.value;
	
	// First validate field
	if(isNaN(intAddresses)) {
		alert('Please enter a valid number of addresses.');
	}
	else {
		
		// Certification Processing Fee
		intTotal = intTotal + (50 * intAddresses);
		
		// Document Processing Fee
		if(intAddresses <= 10)
			intTotal = intTotal + (65 * intAddresses);
		else if(intAddresses <= 50)
			intTotal = intTotal + (50 * intAddresses);
		else
			intTotal = intTotal + (38 * intAddresses);
		
		// Extra services
		if(document.hers_calculator.duct_leakage.checked == true)
			intTotal = intTotal + (200 * intAddresses);
		if(document.hers_calculator.txv.checked == true)
			intTotal = intTotal + (25 * intAddresses);
		if(document.hers_calculator.blower_door.checked == true)
			intTotal = intTotal + (35 * intAddresses);
		if(document.hers_calculator.eer.checked == true)
			intTotal = intTotal + (50 * intAddresses);
		
		// Update field
		document.getElementById('total').innerHTML = '$' + intTotal.toFixed(2);
	}		
}