Read the server response correctly in the GlideAjax callback.

01var ga = new GlideAjax('UserUtils');
02ga.addParam('sysparm_name', 'getManager');
03ga.addParam('sysparm_user', g_user.userID);
04ga.getXMLAnswer(function(answer) {
05  ▢ ▢ ▢ ▢;
06});