var DateControl =
{
    Validate: function(id) {
        var gun = document.getElementById(id + 'gun');
        var ay = document.getElementById(id + 'ay');
        var yil = document.getElementById(id + 'yil');

        var dt =  gun.options[gun.selectedIndex].value + '.' + ay.options[ay.selectedIndex].value + '.' + yil.options[yil.selectedIndex].value;
        document.getElementById(id).value = dt;
    }
}