function $(el) { return document.getElementById(el); }

var calc_wo_disposal = 0;
var calc_wo_total = 0;
var calc_w_cost = 0;
var calc_w_life = 0;
var calc_w_replace = 0;
var calc_w_disposal = 0;
var calc_w_total = 0;
var calc_total = 0;
var calc_payoff = ' ';
var calc_times; //document.forms['calc']['calc_times'];

function calc_set(id,val,cur){ if(isNaN(val)) cur?('$'+val.toFixed(2)):val; else $(id).innerHTML=cur?('$'+val.toFixed(2)):val; }
function calc_output() { calc_set('calc_wo_disposal',calc_wo_disposal,true);calc_set('calc_wo_total',calc_wo_total,true);calc_set('calc_w_cost',calc_w_cost,true);calc_set('calc_w_life',calc_w_life);calc_set('calc_w_replace',calc_w_replace);calc_set('calc_w_disposal',calc_w_disposal,true);calc_set('calc_w_total',calc_w_total,true);calc_set('calc_total',calc_total,true);calc_set('calc_payoff',calc_payoff,false);}

function calc_reset(full) {
  calc_wo_disposal = 0;
  calc_wo_total = 0;
  calc_w_cost = 0;
  calc_w_life = 0;
  calc_w_replace = 0;
  calc_w_disposal = 0;
  calc_w_total = 0;
  calc_total = 0;
  calc_payoff = ' ';
  if(full){
    $('calc_num').selectedIndex = 0;
    $('calc_cost').selectedIndex = 0;
    $('calc_disposl').selectedIndex = 0;
    for(var i=0;i<calc_times.length;i++) calc_times[i].checked=false;
    $('calc_wo_weeks').selectedIndex = 0;
    $('calc_wo_cost').selectedIndex = 0;
    $('calc_wo_months').selectedIndex = 0;
    $('calc_w_rate').selectedIndex = 0;
    $('calc_w_weeks').selectedIndex = 0;
  }
  calc_output();
}

function calc_process() {
	calc_reset();
	calc_times = document.forms['calc']['calc_times'];
  var calc_num = $('calc_num').value;
  var calc_cost = $('calc_cost').value;
  var calc_disposl = $('calc_disposl').value;
  var calc_time = 0
  //var calc_payoff = 0
  for(var i=0;i<calc_times.length;i++) if(calc_times[i].checked) calc_time = calc_times[i].value;
  var calc_wo_weeks = $('calc_wo_weeks').value;
  var calc_wo_cost = $('calc_wo_cost').value;
  var calc_wo_months = $('calc_wo_months').value;
  var calc_w_rate = $('calc_w_rate').value;
  var calc_w_weeks = $('calc_w_weeks').value;
  if ((calc_num>0) && (calc_cost>0) && (calc_disposl>0) && (calc_wo_weeks>0) && (calc_wo_cost>0) && (calc_wo_months>0) && (calc_w_rate>0) && (calc_w_weeks>0) && (calc_time>0)) {
    //without
    calc_wo_disposal=((12/calc_wo_months)*calc_disposl)*calc_num;
    calc_wo_total = (((52/calc_wo_weeks)*(calc_wo_cost*calc_num))+(calc_num*calc_cost)*(12/calc_wo_months)+(12/calc_wo_months)*calc_disposl*calc_num);
    //with
    calc_w_cost = Math.round((52/calc_w_weeks)*(calc_w_rate*0.1));
    calc_w_life = calc_time;
    calc_w_replace = (calc_time*calc_wo_months);
    calc_w_disposal = ((12/calc_w_replace)*calc_disposl)*calc_num;
    calc_w_total = ((calc_num*calc_cost)*(12/calc_w_replace)+(calc_disposl*(52/calc_w_replace)*calc_num)+calc_w_cost);
    //total
    calc_total = calc_wo_total-calc_w_total;
    calc_payoff = roundNumber((12750/calc_total)*12, 1);
  }
	calc_output();
}


function roundNumber(num, dec) {
	var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
	return result;
}
//recalc();
//calc_reset(true);