var total_payment_percently="", total_over_month="";
// console.log("total_payment_percently: ", total_payment_percently )
// console.log("payment_percently:", payment_percently)


function calculate() {
    document.getElementById('calendar').innerHTML = '';

    var credit_sum = document.getElementById('credit_sum').value;
    var initial_percent = Number(document.getElementById('initial_percent').value);
    var percent_yearly = Number(document.getElementById('percent_yearly').value);
    var period_yearly = Number(document.getElementById('period_yearly').value);
    var calendar_year = Number(document.getElementById('calendar_year').value);
    var calendar_month = Number(document.getElementById('calendar_month').value);

    var initial_pay_sum = credit_sum * initial_percent / 100;
    document.getElementById('initial_pay_sum').innerHTML = initial_pay_sum;

    var given_credit_sum = credit_sum - initial_pay_sum;
    document.getElementById('given_credit_sum').innerHTML = given_credit_sum;

    var payment_monthly = given_credit_sum / (period_yearly * 12);
    document.getElementById('payment_monthly').innerHTML = payment_monthly;
    var main_debt = given_credit_sum;


    for (var i = 1; i <= period_yearly * 12; i++) {
        var payment_percently = (main_debt * (percent_yearly / 12)) / 100;
        var over_month = payment_percently + payment_monthly;
        document.getElementById('calendar').innerHTML += ('<tr>' +
            '<td>' + i + '</td>' +
            '<td></td>' +
            '<td></td>' +
            '<td>' + main_debt + '</td>' +
            '<td>' + payment_monthly + '</td>' +
            '<td>' + payment_percently + '</td>' +
            '<td>' + over_month + '</td>' +
            '</tr>');
        main_debt = main_debt - payment_monthly;

        Number(total_payment_percently += Number(payment_percently));
        Number(total_over_month +=Number(over_month));


    }


    document.getElementById('amount_informations').innerHTML = (

        '<tr>' + '<th></th>' + '<th></th>' + '<th></th>' + '<th colspan="3">' + '<h2>Total yearly amounts:</h2>' + '</th>' + '</tr>' +
        '<tr>' +
        '<td colspan="3">' + '<h3>Total payment percently:</h3>' + '</td>' +
        '<td></td>' +
        '<td></td>' +
        '<td></td>' +
        '<td>'+ '<strong>'+total_payment_percently+'</strong>'+'</td>' +
        '</tr>'
    );
}