function formatDollars(amount){
 var i = parseFloat(amount);
 if(isNaN(i)) { i = 0.00; }
 i = parseInt((Math.abs(i) + .005));
 var numArr=((new String(i).split('')).reverse());
	// add commas
 for(i=3;i<numArr.length;i+=3){ numArr[i]+=','; }
	// return with currency symbol and asterisk
 return '$' + numArr.reverse().join('');
}

function calculateSavings(){
  var energyBill = parseFloat($('#electric-bill').val());
  var gasBill = parseFloat($('#gas-bill').val());
  var waterBill = parseFloat($('#water-bill').val());
 // calculate savings
  var monthlyTot = energyBill + gasBill + waterBill;
  var totSavingsLow = monthlyTot * .8;
  var totSavingsHigh = monthlyTot * .7;
 //normal bills  
  $('#n-06').html( formatDollars( monthlyTot * 06 ));
  $('#n-12').html( formatDollars( monthlyTot * 12 ));
  $('#n-36').html( formatDollars( monthlyTot * 36 ));
 //with savings
  $('#s-06').html( formatDollars( totSavingsHigh * 06 ) + " <span style =\"font-weight:normal;\">-</span> " + formatDollars( totSavingsLow * 06 ));
  $('#s-12').html( formatDollars( totSavingsHigh * 12 ) + " <span style =\"font-weight:normal;\">-</span> " + formatDollars( totSavingsLow * 12 ));
  $('#s-36').html( formatDollars( totSavingsHigh * 36 ) + " <span style =\"font-weight:normal;\">-</span> " + formatDollars( totSavingsLow * 36 ));

  //$('#n-range').html( savings6 + ' - ' + savings180 );

  return false;
}

function floor(number){
  return Math.floor(number*Math.pow(10,2))/Math.pow(10,2);
}

function dosum()
{
  var mi = document.temps.IR.value / 1200;
  var base = 1;
  var mbase = 1 + mi;
  for (i=0; i<document.temps.YR.value * 12; i++)
  {
    base = base * mbase
  }
  document.temps.PI.value = floor(document.temps.LA.value * mi / ( 1 - (1/base)))
  document.temps.MT.value = floor(document.temps.AT.value / 12)
  document.temps.MI.value = floor(document.temps.AI.value / 12)
  var dasum = document.temps.LA.value * mi / ( 1 - (1/base)) +
        document.temps.AT.value / 12 + 
        document.temps.AI.value / 12;
  document.temps.MP.value = floor(dasum);
}


function calculateMortgage(){
  var mortgageAmount = parseFloat($('#mortgage-amount').val());
  var interestRate = parseFloat($('#interest-rate').val());
  var loanLength = parseFloat($('#loan-length').val());
		
 // calculate payment
  var mi = interestRate / 1200;
  var base = 1;
  var mbase = 1 + mi;
  for (i=0; i < loanLength * 12; i++){
    base = base * mbase;
  }
		var monthlyPayment = floor(mortgageAmount * mi / ( 1 - (1/base)));
	
 //display payment
  $('#monthly-payment').html( formatDollars( monthlyPayment ) );

  return false;
}