function CheckItCZ(form_fields){
  OK = true;
  Err = '';
  
  if(form_fields.jmeno.value == ""){
    Err = Err+'Musíte zadat Vaše jméno.\n';
    OK =  false;
  }

  if(form_fields.prijmeni.value == ""){
    Err = Err+'Musíte zadat Vaše příjmení.\n';
    OK =  false;
  }

  if(form_fields.telefon.value == ""){
    Err = Err+'Musíte zadat Váš telefon.\n';
    OK =  false;
  }

  if(form_fields.email.value == "") {
    Err = Err+'Musíte zadat Váš E-mail.\n';
    OK = false;
  }
  
  if(!OK)
    alert(Err);
  
  return OK;
  
}

function CheckItEN(form_fields){
  OK = true;
  Err = '';
  
  if(form_fields.jmeno.value == ""){
    Err = Err+'You must enter your name.\n';
    OK =  false;
  }

  if(form_fields.prijmeni.value == ""){
    Err = Err+'You must enter your surname.\n';
    OK =  false;
  }
  
    if(form_fields.telefon.value == ""){
    Err = Err+'You must enter your phone.\n';
    OK =  false;
  }

  if(form_fields.email.value == "") {
    Err = Err+'You must enter your email address.\n';
    OK = false;
  }
  
  if(!OK)
    alert(Err);
  
  return OK;
  
}