//<![CDATA[

var interestOnly = 9999;

var totalOwed;         // total owed
var totalOwed_pmonth;  // total owed per month
	
var newLoanResult;     // total new loan required
var newOwed_pmonth;    // total new owed per month

function calculate() {
  var form = document.getElementById('debt-calc-form');
	
  // calc total owed
	totalOwed = parseFloat(form.amount_bankloans.value) + parseFloat(form.amount_catalogues.value) + parseFloat(form.amount_creditcards.value) + parseFloat(form.amount_storecards.value) + parseFloat(form.amount_carloans.value) + parseFloat(form.amount_other.value);
  // calc total monthly payments
	totalOwed_pmonth = parseFloat(form.amount_bankloans_pmonth.value) + parseFloat(form.amount_catalogues_pmonth.value) + parseFloat(form.amount_creditcards_pmonth.value) + parseFloat(form.amount_storecards_pmonth.value) + parseFloat(form.amount_carloans_pmonth.value) + parseFloat(form.amount_other_pmonth.value);

	//if ((totalOwed > 0) && (totalOwed_pmonth > 0)) {
	  // valid amounts
		newLoanResult = Math.round(totalOwed * 100) / 100;
		form.result_newloan.value = newLoanResult;
		totalOwed_pmonth = Math.round(totalOwed_pmonth * 100) / 100;
		form.result_oldpayment.value = totalOwed_pmonth;
	//}

  //if ((newLoanResult >= 5000) || (newLoanResult <= 500000)) {
    // valid
    if (form.termselect.options[form.termselect.selectedIndex].value == interestOnly) {
      // interest only
      interestCalculation(form);
    } else {
      // normal
      loanCalculation(form);
    }
  //} else {
    // invalid
  //  alert("Loans range from £5,000 to £500,000. Please enter a value in this range.");
  //}
}

function interestCalculation(form){
  // these loan boundaries and rates need changing according to need
  
  if ((newLoanResult > 4999) && (newLoanResult <= 9999))       
		interest = 0.01000;
	else if ((newLoanResult > 9999) && (newLoanResult <= 19999))
		interest = 0.0090;
	else if ((newLoanResult > 19999) && (newLoanResult <= 50000))
		interest = 0.00790;

  insertNewPayment(form, newLoanResult * interest);
}

function loanCalculation(form){
  // these loan boundaries and rates need changing according to need
  
	var termSelected = form.termselect.options[form.termselect.selectedIndex].value;
	
	if ((newLoanResult > 4999) && (newLoanResult <= 9999))       
		interest = 0.010234;
	else if ((newLoanResult > 9999) && (newLoanResult <= 19999))
		interest = 0.0091;
	else if ((newLoanResult > 19999) && (newLoanResult <= 50000))
		interest = 0.00797;
  
  insertNewPayment(form, ((newLoanResult * interest) / (1 - Math.pow((1 + interest), -termSelected))));
}


function insertNewPayment(form, val){
	form.result_newpayment.value = Math.round(parseFloat(val) * 100) / 100;
}

//]]>