var obr_1 = new Image();
var obr_2 = new Image();
var obr_3 = new Image();
var obr_4 = new Image();
var obr_5 = new Image();
obr_1.src = 'img/drbyt_blue.jpg';
obr_2.src = 'img/krokzakrokem_blue.jpg';
obr_3.src = 'img/podklady_blue.jpg';
obr_4.src = 'img/aboutus_blue.jpg';
obr_5.src = 'img/kontakt_blue.jpg';

function countsplatka() 
{
  vyseuveru = document.calc.vyseuveru.value;
  dobauveru = document.calc.dobauveru.value;
  urokovasazba = document.calc.sazba.value;
  vyseuveru = vyseuveru.replace(",",".");
  dobauveru = dobauveru.replace(",",".");
  urokovasazba = urokovasazba.replace(",",".");
  vypocet1=vyseuveru*urokovasazba/1200;
  vypocet2=1+urokovasazba/1200;
  vypocet3=(-1*dobauveru)*12;
  vysesplatky=vypocet1/(1-Math.pow(vypocet2,vypocet3));
  vysesplatky=Math.round(vysesplatky);
  if (vyseuveru == 0) { vysesplatky = 0;  }
  if (dobauveru == 0) { vysesplatky = 0;  }
  if (urokovasazba == 0) { vysesplatky = 0;  }
  document.calc.splatka.value = vysesplatky;
  
}
function testpoli(pole) {
  hodnota = pole.options[pole.selectedIndex].value;
  if(hodnota == "1") 
  {
  document.getElementById("vkatastru").disabled = false;
  document.getElementById("prevoddoov").disabled = false;
  document.getElementById("ltv1s").style.display = 'none';
  document.getElementById("ltv2s").style.display = 'block';
  }
  else
  {
  document.getElementById("vkatastru").disabled = true;
  document.getElementById("prevoddoov").disabled = true;
  }
  if(hodnota == "0") 
  {
  document.getElementById("ltv1s").style.display = 'block';
  document.getElementById("ltv2s").style.display = 'none';
  document.getElementById("ltv1s").disabled = false;
  } 
  if(hodnota == "2") 
  {
  document.getElementById("ltv1s").style.display = 'block';
  document.getElementById("ltv2s").style.display = 'none';
  }
}