var usePerl = true;
var total_loan = 0;
var total_pay = 0;
function addLoan(field){
	var f = document.mortgage_calculator;
	window["total_"+field] = 0;
	var error = false;
	f[field+"_total"].value = "";
	for(i=1;i<6;i++){
		n = stripCurrency(f[field + i].value);
		if(isNaN(n)){
			f[field + i].value = 0;
		}else{
			if(n == ""){n = 0;}
			window["total_"+field] += parseInt(n);
		}
	}
	// output
	f[field+"_total"].value = "£"+formatCurrency(window["total_"+field]);
}

function calculate(){
	var f = document.mortgage_calculator;
	var errors = "";
	var good_result = false;
	
	// error check
	outstanding_mortgage = stripCurrency(f.outstanding_mortgage.value);
	if(isNaN(outstanding_mortgage) || outstanding_mortgage == ""){
		f.outstanding_mortgage.value = "";
		errors += "Outstanding mortgage\n";
	}else{
		outstanding_mortgage = parseInt(outstanding_mortgage);
	}
	
	current_monthly_payment = stripCurrency(f.current_monthly_payment.value);
	if(isNaN(current_monthly_payment) || current_monthly_payment == ""){
		f.current_monthly_payment.value = "";
		errors += "Current monthly payment\n";
	}else{
		current_monthly_payment = parseInt(current_monthly_payment);
	}
	
	prop_value = stripCurrency(f.property_value.value);
	if(isNaN(prop_value) || prop_value == ""){
		f.property_value.value = "";
		errors += "Current property value\n";
	}else{
		prop_value = parseInt(prop_value);
	}
	
	if(usePerl){
		// check contact details
		if(f.postcode.value == ""){
			errors += "Postcode of property\n";
		}
		if(f.tel.value == ""){
			errors += "Telephone number\n";
		}
		if(f.name.value == ""){
			errors += "Your name\n";
		}
	}
	if(errors.length > 0){
		alert("Please check the following are correct:\n\n" + errors);
	}else{
		// use javascript
		assummed_remortgage = Math.round(prop_value * 0.90);
		term = f.term.options[f.term.selectedIndex].value;
		// repayment calc only:
		rate = f.interest_rate.value;
		rate_per_month = rate/1200;
		m =  term * 12;
		loan = Math.pow(1+rate_per_month, m);
		
		mortgage_and_debts = outstanding_mortgage + total_loan;
		
		equity = (assummed_remortgage > mortgage_and_debts) ? true:false;
		if(equity){
			// recalc to only use equity to cover loans and initial mortgage
			new_mortgage = mortgage_and_debts;
			monthly_repayment = Math.floor(new_mortgage/((1-(1/loan))/rate_per_month));
			monthly_saving = (current_monthly_payment + total_pay) - monthly_repayment;
			
			if(monthly_saving > 0){
				// use javascript to calc
				f.new_monthly_repayment.value = "£"+formatCurrency(monthly_repayment);
				f.monthly_saving.value = "£"+formatCurrency(monthly_saving);
				f.new_mmortgage.value = "£"+formatCurrency(new_mortgage);
				good_result = true;				
			}else{
				// not enough equity to cover loans
				//urchinTracker('/t/bad-credit/debt_consolidation/equity-no/');
				
				good_result = false;
			}
		}else{
			// no equity
			good_result = false;
		}
		
		if(good_result){
			if(usePerl){
				f.submit();
			}else{
				document.getElementById("timer").style.display = "none";
				
				document.getElementById("debt_consolidation_form").style.display = "none";
				document.location.href += "#";
				document.getElementById("sorry").style.display = "none";
				document.getElementById("results").style.display = "block";
			}
		}else{
			document.getElementById("debt_consolidation_form").style.display = "none";
			document.location.href += "#";
			document.getElementById("sorry").style.display = "block";
			document.getElementById("results").style.display = "none";
		}
	}
}