// eurokalkulacka
  var kurz = 30.1260;
  var maxCelychCisel = 10;
  var maxDesatinnychCiselSkk = 2;
  var maxDesatinnychCiselEur = 2;

  function ibaCisla(text, max) {
  var cnt = text.length;
  var ret = '';
  var nemamBodku = true;
  var predBodkou = 0;
  var zaBodkou = 0;
  for (i=0;i<cnt;i++) {
  var znak = text.substring(i,i+1);
  if (znak == ',') {znak = '.';}
  if (znak >= '0' && znak <= '9') {
  if (nemamBodku) {
  if (predBodkou<maxCelychCisel) {
  ret = ret + znak;
  predBodkou++;
  }
  // max. desatinnych sicel;
  } else {
  if (zaBodkou<max) {
  ret = ret + znak;
  zaBodkou++;
  }
  }
  }
  if (znak == '.' && nemamBodku) {
  nemamBodku = false;
  ret = ret + znak;
  }
  }
  if (ret=='.') {ret = '';}
  return ret;
  }

  function ciarka(num) {
  	return num.replace(".",",");
  }
  
  function writeCurr(skk, eur, event) {
  if ((event.keyCode>34 && event.keyCode<41)) {return;}
  if (skk == null) {
  eur = ibaCisla(eur,maxDesatinnychCiselEur);
  skk = (eur*kurz).toFixed(2)*1;
  if (skk == 0) {skk = '';}
  } else {
  skk = ibaCisla(skk,maxDesatinnychCiselSkk);
  eur = (skk/kurz).toFixed(maxDesatinnychCiselEur)*1;
  if (eur == 0) {eur = '';}
  }
  if (document.getElementById('skk').value!=skk) {document.getElementById('skk').value = ciarka(skk+'');}
  if (document.getElementById('eur').value!=eur) {document.getElementById('eur').value = ciarka(eur+'');}
  }
  
  function writeHypo(event) {
    if ((event.keyCode>34 && event.keyCode<41)) { return; }
	if ((document.getElementById('vyska').value == null || document.getElementById('vyska').value.length == 0) || (document.getElementById('dlzka').value == null || document.getElementById('dlzka').value.length == 0) || (document.getElementById('sadzba').value == null || document.getElementById('sadzba').value.length == 0)) { 
		document.getElementById('splatka').value = "Incomplete data";
	} else {
		if (ibaCisla(document.getElementById('vyska').value, 2) && ibaCisla(document.getElementById('dlzka').value, 2) && ibaCisla(document.getElementById('sadzba').value, 2)) {
			var princ = ibaCisla(document.getElementById('vyska').value, 2);
			var term  = ibaCisla(document.getElementById('dlzka').value, 2)*12;
			var intr  = ibaCisla(document.getElementById('sadzba').value, 4)/1200;
			var splatka = princ * intr / (1 - (Math.pow(1/(1 + intr), term)));
			document.getElementById('splatka').value = ciarka((splatka.toFixed(2)*1)+'');
			document.getElementById('vyska').value = ciarka(princ+'');
			document.getElementById('dlzka').value = ciarka(ibaCisla(document.getElementById('dlzka').value, 2)+'');
			document.getElementById('sadzba').value = ciarka(ibaCisla(document.getElementById('sadzba').value, 4)+'');
		} else {
			document.getElementById('splatka').value = "Data error";
		}
	}
	// payment = principle * monthly interest/(1 - (1/(1+MonthlyInterest)*Months))
  }