function podmienky(){

      var nick = document.formular.reg_nick.value;
      var heslo = document.formular.reg_heslo.value;
      var overenie = document.formular.reg_overenie.value;
      
      if(heslo!=overenie && overenie.length>0){
         document.getElementById("chyba_overenie").innerHTML = "Heslá sa nezhodujú!";
      }  else  {
         document.getElementById("chyba_overenie").innerHTML = "";
      }
      
      if(heslo.length<5 && heslo.length>0){
        document.getElementById("chyba_heslo").innerHTML = "Min. 5 znakov";
      }  else  {
        document.getElementById("chyba_heslo").innerHTML = "";
      }
      
      if(nick.length<4){
         document.getElementById("chyba_nick_dlzka").innerHTML = "Min. 4 znaky";
      }  else  {
         document.getElementById("chyba_nick_dlzka").innerHTML = "";
      }
      
      if (window.ActiveXObject) {
         httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
      }  else  {
         httpRequest = new XMLHttpRequest();
      }
      
      httpRequest.open("GET", "kontrolanicku.php?nick="+nick, true);
      httpRequest.onreadystatechange= function () {processRequest(); } ;
      httpRequest.send(null);

}


function processRequest()
{
  if (httpRequest.readyState == 4)
  {
    if(httpRequest.status == 200)
    {
      var mistoZobrazeni = document.getElementById("chyba_nick");
      mistoZobrazeni.innerHTML = httpRequest.responseText;
    }
    else
    {
        //alert("Chyba pri nacitani stranky");
    }
  }
}