I am unable to get the updated value from the function. The code is similar to Javascript and ajax.
var created_ByRegion = g_form.getValue('u_region');
var g_number = g_form.getValue("u_number");
var response = '';
var ga = new GlideAjax('getRegionUsers');
ga.addParam('sysparm_name', "getUsers");
ga.addParam('sysparm_region', created_ByRegion); //Onchange field is reference field to sys_user table
ga.getXMLAnswer(function(answer) {
var response = answer;
});
alert(response);