function kontrola_step1(form) {

 if (
     (form.heslo.value == "") ||
     (form.heslo2.value == "") ||
     (form.heslo.value != form.heslo2.value ) ||     
     (form.jmeno.value == "") ||
     (form.prijmeni.value == "") ||
     (form.tel.value == "")
     )
   {
      alert ("Vyplňte prosím všechny povinné údaje!\nPlease fill all required data!");
      return false;
   } 
     
     
   
   if (form.email.value !="") {


      if (window.RegExp)
      {
      re = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,3}$");
      if (!re.test(form.email.value))
      {
      alert("Chyba formátu emailu. Prosím vložte správný email.\nBad email format. Please write email correctly.");
      form.email.focus();
      return false;
      }
      }

 
}
}


function kontrola_step2(form) {

 if (
     (form.stat.value == "") ||
     (form.provincie.value == "") ||
     (form.mesto.value == "") ||
     (form.ulice.value == "") ||
     (form.psc.value == "")
     )
   {
      alert ("Vyplňte prosím všechny povinné údaje!\nPlease fill all required data!");
      return false;
   } 

}


function kontrola_step3(form) {

 if (
     (form.nazev.value == "") ||
     (form.pocetosob.value == "") ||
     (form.loznic.value == "") ||
     (form.spani.value == "") ||
     (form.koupelen.value == "") ||
     (form.podlahovka.value == "") ||
     (form.typubytovani.value == "") ||
     (form.druhubytovani.value == "") ||
     (form.wc.value == "")
     )
   {
      alert ("Vyplňte prosím všechny povinné údaje!\nPlease fill all required data!");
      return false;
   } 

}


function kontrola_step4(form) {

 if (
     (form.popis_domova.value == "") ||
     (form.popis_sousedstvi.value == "") ||
     (form.popis_osoby.value == "")
     )
   {
      alert ("Vyplňte prosím všechny povinné údaje!\nPlease fill all required data!");
      return false;
   } 

}

function kontrola_poslatvzkaz(form) {
     
 if (
     (form.email.value == "") ||
     (form.jmeno.value == "") ||
     (form.tel.value == "") ||
     (form.datum.value == "") ||
     (form.cas.value == "") ||
     (form.pokoje.value == "") ||
     (form.nahoda.value == "")
     )
   {  
   
   if($_SESSION['lg'] == "cz")
      {
      alert ("Vyplňte prosím všechny povinné údaje!");
      }
      if($_SESSION['lg'] == "en")
      {
      alert("Please fill in all the required informations!");
      }
      return false;
   } 

   
   if (form.email.value !="") {


      if (window.RegExp)
      {
      re = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,3}$");
      if (!re.test(form.email.value))
      {
      if($_SESSION['lg'] == "cz")
      {
      alert("Chyba formátu emailu. Prosím vložte správný email.");
      }
      if($_SESSION['lg'] == "en")
      {
      alert("You have entered the wrong email adress.");
      }
      form.email.focus();
      return false;
      }
      }

   }

   
   if (form.email2.value !="") {


      if (window.RegExp)
      {
      re = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,3}$");
      if (!re.test(form.email2.value))
      {
      alert("Chyba formátu emailu. Prosím vložte správný email.");
      form.email2.focus();
      return false;
      }
      }

   }


}

function kontrola_filtrace(form) {
     
 if (
     (form.znacka.value == "") &&
     (form.fuel.value == "") &&
     (form.od.value == "") &&
     (form.do.value == "") &&
     (form.model.value == "")
     )
   {
      alert ("Zvolte prosím alespoň jedno kriterium!");
      return false;
   } 


}