// Pmac Mortgage Calculator

function Calc(form) {

        var x, y, incm, intRate = 0;

                intRate = form.rate.value / 100 / 12;

                p = form.term.value * 12;

                form.down.value = form.price.value * form.pdown.value / 100;

                form.loan.value = form.price.value - form.down.value;

                x = form.loan.value * intRate * Math.pow(1 + intRate, p);

                y = Math.pow(1 + intRate, p) - 1;

                form.pni.value = parseInt(x / y);

        

                form.pmirate.value = 0;

                if (form.pdown.value < 20) {

                        form.pmirate.value = .32;

                }

        if (form.pdown.value < 15) {

                        form.pmirate.value = .52;

                }

                if (form.pdown.value < 10) {

                        form.pmirate.value = .78;

                }

                form.pmi.value = parseInt(form.loan.value * form.pmirate.value / 1200);

                form.piti.value = parseInt(form.pni.value) + parseInt(form.pmi.value);

}