Your GB Message put somewhere...
Code:
<div id="GB_Message" style="display:none">
Message for GB customers...
</div>
CSS...
Code:
#GB_Message { color: red; font-size: 20px; }
Script...
Code:
<script>
$(document).ready(function() {
var $selectedCountry = $('select#b_country').val();
if ($selectedCountry == 'GB') {
$('#GB_Message').removeAttr('style');// Show message
} else {
$('#GB_Message').css('display', 'none');// Hide message
}
$('select#b_country').on('change', function() {
var $modifiedCountry = $(this).val();
if ($modifiedCountry == 'GB') {
$('#GB_Message').removeAttr('style');// Show message
} else {
$('#GB_Message').css('display', 'none');// Hide message
}
});
});
</script>
Untested, but should probably work...