function isValidDate(yearStr, monthStr, dayStr){
    if (yearStr != parseInt(yearStr)) {
        return false;
    }
    if (monthStr != parseInt(monthStr)) {
        return false;
    }
	if (dayStr != parseInt(dayStr)) {
        return false;
    }

    year = parseInt(yearStr);
    month = parseInt(monthStr)-1; // Sausis - 0
    day = parseInt(dayStr);
    if (month < 0 || month > 11) {
        return false;
    }
	if (day < 1 || day > 31) {
        return false;
    }
	if (year < 1800 || year > 2500) {
        return false;
    }
    var date = new Date(year, month, day);
    if (date.getDate() != day) {
        alert("Neteisinga data");
        return false;
    }
	else return true;
}