function str_replace ( search, replace, subject ) {

    var result = "";
    var prev_i = 0;
    for (i = subject.indexOf(search); i > -1; i = subject.indexOf(search, i)) {
        result += subject.substring(prev_i, i);
        result += replace;
        i += search.length;
        prev_i = i;
    }

    return result + subject.substring(prev_i, subject.length);
}

function round(num, mp) {
          if (mp == null)
            mp = 2;

          mpm = Math.pow(10, mp);
          if (num < 0) {
            num = -num;
            sign = "-";
          } else {
            sign = "";
          }
          pomnum = num * mpm;
          pomnum = Math.ceil(pomnum - 0.5);
          j = -1;
          retstring = "";
          while  ((pomnum > 0) || (mp > 0)) {
            cyfra = (pomnum % 10);
            retstring = cyfra + retstring;
            pomnum = pomnum / 10;
            pomnum = Math.floor(pomnum);
            if (j >= 0) {
              j++;
              if (((j % 3) == 0) && pomnum)
                retstring = " " + retstring;
            } else {
              mp--;
              if (mp == 0) {
                retstring = "," + retstring;
                j = 0;
              }
            }
          }
          if (retstring != 0)
            return sign + retstring;
          else
            return retstring;
        }

function JakiKredyt(oForm) {
  var A = parseFloat(oForm.rata.value.replace(/,/,'.'));
  var r = parseFloat(oForm.procent.value.replace(/,/,'.'));
  var n = parseFloat(oForm.okres.value.replace(/,/,'.'));
  var nRodzaj = parseInt(oForm.rodzaj.value);
  var m = 12.0;

  sResult = '';

  // raty równe
  if(1 == nRodzaj) {
    var q = 1 + (r*0.01/m);
    var qn = Math.pow(q,n);
    var S = A * (qn-1)/(qn*(q-1));
    S = Math.round(S*100)/100;

    sResult = "Otrzymasz kredyt w wysokości: <b class='red'>" + round(S, 2) + " zł</b>";
  }
  // raty malejące
  else if(2 == nRodzaj) {
    var S = A / (1.0/n + r*0.01/12);
    S = Math.round(S*100)/100;

    sResult = "Wysokość kredytu: <b class='red'>" + round(S, 2) + "</b>";
  }

	document.getElementById('plan').innerHTML = sResult;

}