[jQuery] Problems getting validate plugin to work with select box

[paulswansea]

I'm trying to get the validate plugin to work with a select box, but
for some reason, it wont validate if i select a country, what am i
doing wrong?

<form id="testform" method="post">
        <select name="country" id="country">
                <option value="">Select a country</option>
                <option value="AF">Afghanistan</option>
                <option value="AX">Aland Islands</option>
                <option value="AL">Albania</option>
                <option value="GB.WLS">Wales</option>
        </select>
        <input id="submitbtn" name="submitbtn" type="submit" />
</form>
<script type="text/javascript">
        $('#testform').validate({
                messages : {
                        country : {
                                required : 'select country',
                                minlength : 'choose a country'
                        },
                },
                rules : {
                        country : {
                                required : true,
                                minlength: 2
                        },
                },
                success: function(label) {
                        label.html("&nbsp;").addClass("checked");
                }

        });

</script>