var prestupny_rok_err_message = new Array();

prestupny_rok_err_message["cz"] = "Pros?m, ?nor nem? v zadan?m roce 29 dn?. Zadan? rok nen? p?estupn?.";
prestupny_rok_err_message["en"] = "Please, February in inserted year hasn't got 29 days";


/********************** NEMENIT ******************/

function showwin(name, size) {
  attrbts = size + ",resizable=no,toolbar=no,location=no,directories=no,statusbar=no,menubar=no,top=50,left=50"
  window.open(name, "CALENDAR", attrbts);
} 

function isPrestupnyRok(year) { 
  return (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) ? 1 : 0;
}

function checkDatum(input, jazyk) {
   
  var d_parse = input.value.split('. ');
  
  if (d_parse[1]-1 == 1 && !isPrestupnyRok(d_parse[2]) && d_parse[0] == 29) {
    alert(prestupny_rok_err_message[jazyk]);
    return false;
  }
  return true;

}