function mycalc() {
    
	var main_income_total 	= 0;
    var co_income_total 	= 0;
    var main_expense_total	= 0;
    var co_expense_total 	= 0;
    
    // INCOME CALCULATIONS
    // INCOME OF MAIN APPLICANT
    main_income_total = 
        parseFloat(document.getElementById('main_income_salary').value) + 
        parseFloat(document.getElementById('main_income_comm').value) + 
        parseFloat(document.getElementById('main_income_housing').value) + 
        parseFloat(document.getElementById('main_income_investments').value) + 
        parseFloat(document.getElementById('main_income_rental').value) +                         
        parseFloat(document.getElementById('main_income_other').value); 

    // INCOME OF CO-APPLICANT
    co_income_total = 
        parseFloat(document.getElementById('co_income_salary').value) + 
        parseFloat(document.getElementById('co_income_comm').value) + 
        parseFloat(document.getElementById('co_income_housing').value) + 
        parseFloat(document.getElementById('co_income_investments').value) + 
        parseFloat(document.getElementById('co_income_rental').value) +                         
        parseFloat(document.getElementById('co_income_other').value);                

    document.getElementById('main_income_total').firstChild.nodeValue = "R " + formatCalc(main_income_total);
    document.getElementById('co_income_total').firstChild.nodeValue = "R " + formatCalc(co_income_total);
    
    // EXPENSE CALCULATIONS
    // EXPENSES OF MAIN APPLICANT
    main_expense_total = 
        parseFloat(document.getElementById('main_expense_bond').value) + 
        parseFloat(document.getElementById('main_expense_hp').value) + 
        parseFloat(document.getElementById('main_expense_cc').value) + 
        parseFloat(document.getElementById('main_expense_water').value) + 
        parseFloat(document.getElementById('main_expense_rates').value) + 
        parseFloat(document.getElementById('main_expense_stinsurance').value) + 
        parseFloat(document.getElementById('main_expense_lifeinsurance').value) +                                         
        parseFloat(document.getElementById('main_expense_petrol').value) +                                         
        parseFloat(document.getElementById('main_expense_clothing').value) +                                         
        parseFloat(document.getElementById('main_expense_telephone').value) +                                                                 
        parseFloat(document.getElementById('main_expense_tv').value) +                                             
        parseFloat(document.getElementById('main_expense_car').value) +                                         
        parseFloat(document.getElementById('main_expense_food').value) +                                         
        parseFloat(document.getElementById('main_expense_household').value) +                                         
        parseFloat(document.getElementById('main_expense_domestic').value) +                                         
        parseFloat(document.getElementById('main_expense_medical').value) +                                         
        parseFloat(document.getElementById('main_expense_education').value) +                                       
        parseFloat(document.getElementById('main_expense_entertainment').value) +                                         
        parseFloat(document.getElementById('main_expense_maintenance').value) +                                         
        parseFloat(document.getElementById('main_expense_pension').value) +                                         
        parseFloat(document.getElementById('main_expense_medical_aid').value) +                                         
        parseFloat(document.getElementById('main_expense_paye').value) +                                                                                                               
        parseFloat(document.getElementById('main_expense_uif').value) ;

    co_expense_total = 
        parseFloat(document.getElementById('co_expense_bond').value) + 
        parseFloat(document.getElementById('co_expense_hp').value) + 
        parseFloat(document.getElementById('co_expense_cc').value) + 
        parseFloat(document.getElementById('co_expense_water').value) + 
        parseFloat(document.getElementById('co_expense_rates').value) + 
        parseFloat(document.getElementById('co_expense_stinsurance').value) + 
        parseFloat(document.getElementById('co_expense_lifeinsurance').value) +                                         
        parseFloat(document.getElementById('co_expense_petrol').value) +                                         
        parseFloat(document.getElementById('co_expense_clothing').value) +                                         
        parseFloat(document.getElementById('co_expense_telephone').value) +                                                                 
        parseFloat(document.getElementById('co_expense_tv').value) +                                             
        parseFloat(document.getElementById('co_expense_car').value) +                                         
        parseFloat(document.getElementById('co_expense_food').value) +                                         
        parseFloat(document.getElementById('co_expense_household').value) +                                         
        parseFloat(document.getElementById('co_expense_domestic').value) +                                         
        parseFloat(document.getElementById('co_expense_medical').value) +                                         
        parseFloat(document.getElementById('co_expense_education').value) +                                       
        parseFloat(document.getElementById('co_expense_entertainment').value) +                                         
        parseFloat(document.getElementById('co_expense_maintenance').value) +                                         
        parseFloat(document.getElementById('co_expense_pension').value) +                                         
        parseFloat(document.getElementById('co_expense_medical_aid').value) +                                         
        parseFloat(document.getElementById('co_expense_paye').value) +                                                                                                               
        parseFloat(document.getElementById('co_expense_uif').value) ;
        
    document.getElementById('main_expense_total').firstChild.nodeValue = "R " + formatCalc(main_expense_total);
    document.getElementById('co_expense_total').firstChild.nodeValue = "R " + formatCalc(co_expense_total);

    // TOTALS
    var total_income = main_income_total + co_income_total;
    document.getElementById('total_income').firstChild.nodeValue = "R " + formatCalc(total_income);
    
    var total_expenses = main_expense_total + co_expense_total;
    document.getElementById('total_expenses').firstChild.nodeValue = "R " + formatCalc(total_expenses);
    
    var available_income = total_income - total_expenses;
    document.getElementById('available_income').firstChild.nodeValue = "R " + formatCalc(available_income);    

    var calculation_at_prime = (available_income/11.65)*1000;
    document.getElementById('calculation_at_prime').firstChild.nodeValue = "R " + formatCalc(calculation_at_prime); 

}



function formatCalc(num) {
	num = num.toString().replace(/\$|\,/g,'');
	if(isNaN(num))	num = "0";
	
	sign = (num == (num = Math.abs(num)));
	num = Math.floor(num*100+0.50000000001);
	cents = num%100;
	num = Math.floor(num/100).toString();
	
	if(cents<10)	cents = "0" + cents;
	
	for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
		num = num.substring(0,num.length-(4*i+3)) + ',' + num.substring(num.length-(4*i+3));
		
	return (((sign)?'':'-') + '' + num + '.' + cents);
}