
<!--
// variables
// typical costs of installation
var site_micro_e_control = 2195;
var site_basic_install_cost = 300;
var site_cartridge_metatrax_service = (233)+90+110;
var site_water_bootser = 295;
var site_package_price = site_micro_e_control + site_basic_install_cost + site_cartridge_metatrax_service + site_water_bootser;

var noritsu_scaler = 0.65;
var noritsu_micro_e_control = site_micro_e_control*noritsu_scaler;
var noritsu_basic_install_cost = site_basic_install_cost;
var noritsu_cartridge_metatrax_service = (233*noritsu_scaler)+90+110;
var noritsu_water_bootser = site_water_bootser;
var noritsu_package_price = noritsu_micro_e_control + noritsu_basic_install_cost + noritsu_cartridge_metatrax_service + noritsu_water_bootser;

// silver recovery potential
var silver_per_roll = 0.5;
var silver_prints = 0.5; 		// percentage as a fraction
var silver_film = 0.5; 			// percentage as a fraction
var prints_per_roll = 36;
var silver_per_print = silver_per_roll*(silver_prints/prints_per_roll);
var silver_100_prints = 100*silver_per_print;

var unknown = 7500; 			// need name for this
var optimal_column_change = unknown/silver_per_print;

var film_rolls = unknown/silver_per_roll;
var film_rolls_silver = film_rolls*silver_per_roll;

var cds_prints = 50;
var cds = optimal_column_change*cds_prints;
var cds_silver = cds*silver_per_print*cds_prints;

// silver pricing
var silver_oz = 19.45;
var silver_kilo = 600;

function calculate() {
	var films_per_annum = parseFloat(document.getElementById('films_per_annum').value);
	var prints_per_annum = parseFloat(document.getElementById('prints_per_annum').value);
	var haulaway_cost = parseFloat(document.getElementById('haulaway_cost_1').value);

	document.getElementById('basic_cost').innerHTML = "&pound;" + round(site_package_price,2);
	document.getElementById('replacement_cost_1').innerHTML = "&pound;" + round(site_cartridge_metatrax_service,2);

	var revenue = 7.5*silver_kilo;
	document.getElementById('revenue').innerHTML = "&pound;" + round(revenue,2);
	document.getElementById('replacement_cost_2').innerHTML = "&pound;" + round(site_cartridge_metatrax_service,2);

	var net_revenue = revenue-site_cartridge_metatrax_service;
	document.getElementById('net_revenue').innerHTML = "&pound;" + round(net_revenue,2);

	var annum_column_changes = ((films_per_annum*silver_per_roll)+(prints_per_annum*silver_per_print))/unknown;
	document.getElementById('annum_column_changes').innerHTML = round(annum_column_changes,0);
	var annum_net_revenue = annum_column_changes*net_revenue;
	document.getElementById('annum_net_revenue').innerHTML = "&pound;" + round(annum_net_revenue,2);
	var capital_repayment_period = site_package_price/annum_net_revenue;
	document.getElementById('capital_repayment_period').innerHTML = round(capital_repayment_period,2)+" years";

	var yrs_total_columns = annum_column_changes*5;
	document.getElementById('5years_total_columns').innerHTML = round(yrs_total_columns,0);
	var yrs_gross_revenue = revenue*yrs_total_columns;
	document.getElementById('5years_gross_revenue').innerHTML = "&pound;" + round(yrs_gross_revenue,2);
	document.getElementById('5years_capital_cost').innerHTML = "&pound;" + round(site_package_price,2);
	var yrs_revenue_cost = yrs_total_columns*site_cartridge_metatrax_service;
	document.getElementById('5years_revenue_cost').innerHTML = "&pound;" + round(yrs_revenue_cost,2);
	var yrs_operating_cost = site_package_price+yrs_revenue_cost;
	document.getElementById('5years_operating_cost').innerHTML = "&pound;" + round(yrs_operating_cost,2);
	var yrs_profit = yrs_gross_revenue-yrs_operating_cost;
	document.getElementById('5years_profit').innerHTML = "&pound;" + round(yrs_profit,2);
	var yrs_return_total = (yrs_profit/site_package_price)*100;
	document.getElementById('5years_return_total').innerHTML = round(yrs_return_total,0)+"%";
	var yrs_return_average = yrs_return_total/5;
	document.getElementById('5years_return_average').innerHTML = round(yrs_return_average,0)+"%";

	document.getElementById('haulaway_cost_2').innerHTML = "&pound;" + round(haulaway_cost/100,2);
	var haulaway_litre_usage = ((films_per_annum/film_rolls)+(prints_per_annum/optimal_column_change))*4000;
	document.getElementById('haulaway_litre_usage').innerHTML = round(haulaway_litre_usage,2);
	var haulaway_total_cost = haulaway_litre_usage*5*(haulaway_cost/100);
	document.getElementById('haulaway_total_cost').innerHTML = "&pound;" + round(haulaway_total_cost,2);
}

function round(value, places, prefix) {
	var roundVal = "1";

	for (i=0;i<places;i++) {
		roundVal += "0";
	}

	var retVal = Math.round(value*roundVal)/roundVal;
	// convert to string
	retVal = retVal + '';
	// add trailing zeros
	if (places > 0) {
		if (retVal.indexOf(".") != -1) {
			var temp = retVal.substring(retVal.indexOf(".")+1,retVal.length);
			if (temp.length < 2) {
				for (i=1;i<places;i++) {
					retVal += "0";
				}
			}
		} else {
			retVal += ".";
			for (i=0;i<places;i++) {
				retVal += "0";
			}
		}
	}

	if (prefix != null) {
		retVal = prefix + retVal;
	}

	return retVal;
}
//-->