function BTLCalculateRepayment(form){

rate = 0.05
rent = parseFloat(form.rent.value);
mortgageres = rent/rate/1.30*12;
deposit = ((mortgageres/0.85)-mortgageres);
mortgageres = Math.round(mortgageres);
deposit = Math.round(deposit);
form.txtmaxmortgage.value = mortgageres;
form.txtmindeposit.value = deposit;
}

	function MAXCalculateRepayment(form){

// set variables to nil
	
	adj1=0;
	adj2=0;
	res1=0;
	res2=0;
	res3=0;
	restemp=0;
	b1=0;
	b2=0;
	o1=0;
	o2=0;
	l1=0;
	l2=0;
	res=0;

// if no data supplied then give it a nil value

if (form.sal_1.value == ""){
form.sal_1.value = 0
}

if (form.sal_2.value == ""){
form.sal_2.value = 0
}

if (form.bonus_1.value == ""){
form.bonus_1.value = 0
}

if (form.bonus_2.value == ""){
form.bonus_2.value = 0
}

if (form.loan_1.value == ""){
form.loan_1.value = 0
}

if (form.loan_2.value == ""){
form.loan_2.value = 0
}

// collect data from form


	b1 = parseFloat (form.sal_1.value);

    b2 = parseFloat (form.sal_2.value);

	o1 = parseFloat (form.bonus_1.value);
	
	o2 = parseFloat (form.bonus_2.value);

    l1 = parseFloat (form.loan_1.value);

	l2 = parseFloat (form.loan_2.value);






// calculate fields

   adj1= (b1+(0.5*o1)-(l1*12));
   adj2= (b2+(0.5*o2)-(l2*12));
   
	// calculate 4*1st + 1*2nd   
   		res1= (adj1*4.2)+ adj2;
 
	// calculate 1*1st + 4*2nd
		res2= (adj2*4.2)+adj1;

	// calculate 3* Joint
		res3= (adj1+adj2)*3.5;

//calculate highest result

	if (res1>res2) {
		restemp=res1
		}
	if (res2>res1) {
		restemp=res2
		}
	if (res3>restemp) {
		res=res3
		}else{
		res=restemp
		}

            
// populate form boxes to display values
	

	
	form.txtloanvalue.value = res;

	}
	
	
	
function CalculateRepayment(form){
	a = parseFloat(form.mortg_amount.value);
    i = parseFloat(form.interest_amount.value);
	y = parseFloat(form.mortg_term.value);	
	var m1 = (i/100)/12;
	var am1 = (i/100);
	var m2 = a*m1;
	var am2 = a*am1;
	var m4 = -1*y*12;
	var am4 = -1*y;
	var m5 = m1+1;
	var am5 = am1+1;
	var m6 = Math.pow(m5, m4);
	var am6 = Math.pow(am5,am4);
	var m7 = 1-m6;
	var am7 = 1-am6;
	var daily =m2/m7;
	var annual =am2/am7/12;
	var intonly = a*i/1200;
	form.txtrepay.value = Math.round(daily*100)/100;
	form.txtinterest.value = Math.round(intonly*100)/100;
	}