excel CUMIPMT. function in javascript

This is pseudocode, you will need to adjust it:

Object CUMIPMT(double rate, double nper, double pv, double start_period, double end_period, double type)
        {

            if (rate <= 0)
            {
                return "#NUM!";
            }

            if (nper <= 0)
            {
                return "#NUM!";
            }
            nper = (int)nper;

            if (pv <= 0)
            {
                return "#NUM!";
            }

            if (start_period < 1)
            {
                return "#NUM!";
            }
            start_period = (int)start_period;

            if (end_period < 1)
            {
                return "#NUM!";
            }
            end_period = (int)end_period;

            if (start_period > end_period)
            {
                return "#NUM!";
            }

            if (!(type == 0 || type == 1))
            {
                return "#NUM!";
            }

            double value = 0;
            for (int per = (int)start_period; per <= (int)end_period; per++)
            {
                value += IPMT(rate, nper, per, pv, 0, type);
            }

            return value;
        }

        double IPMT(double rate, double nper, double period, double pv, double fv, double type)
        {
            if (rate == 0)
            {
                return 0;
            }
            if (type == 1 && period == 1)
            {
                return 0;
            }
            double pmt = PMT(rate, nper, pv, fv, 0);
            if (type == 0)
            {
                return (pv * Math.Pow(1.0 + rate, period - 1) + pmt * ((Math.Pow(1 + rate, period - 1) - 1) / rate)) * rate * (-1.0);
            }
            else
            {
                double pmt2 = PMT(rate, nper, pv, fv, 1);
                return pmt2 - pmt + (pv * Math.Pow(1.0 + rate, period - 2) + pmt * ((Math.Pow(1 + rate, period - 2) - 1) / rate)) * rate * (-1.0);
            }

        }

        double PMT(double rate, double nper, double pv, double fv, double type)
        {
            if (rate == 0)
            {
                return (-1.0) * (fv + pv) / nper;
            }
            else
            {
                return (-1.0) *
                        ((fv + pv * Math.Pow((1 + rate), nper)) *
                        rate /
                        ((1 + rate * type) * (Math.Pow((1 + rate), nper) - 1))
                    );
            }
        }