app/assets/javascripts/admin/countries.js
jQuery(document).ready(function ($) {
var selected = 1;
$countries_select = $('#countries_select');
$countries_select.on('change', function(element){
var selected = $(element.target).val();
var $link = $('#activate-link');
if (selected) {
url = $link.attr('href', "/admin/config/countries/" + selected + '/activate').click();
}
})
});