[рони]

Melorum,

<script>
$(function() {
function calc(sum,percent,dayCount) {
  percent = Number(percent)||0;
  sum = Number(sum)||0;
  dayCount = Number(dayCount)||0;
  var result = sum*percent;
  for (var i=0;i<dayCount;i++){
    result=result*percent;
  }
  return result;
}
var sum = $('#sum');
var percent = $('#percent');
var days = $('#day');

$('#calcButton').click(
  function () {
      var result = calc(sum.val(),percent.val(),days.val());
      $('#result').html(result);
  }
 )
});
  </script>