How to get login user Manager In SPServices In SHarepoint 2013

<script type="text/javascript">
$(document).ready(function() {


var managerName;
        var userName = $().SPServices.SPGetCurrentUser();
        $().SPServices({
            operation: "GetUserProfileByName",
            async: false,
            AccountName: userName,
            completefunc: function (xData, Status) {
                managerName = $(xData.responseXML).text();
                var managerLength = managerName.length;
                var indexofManager = managerName.indexOf("Manager");
                managerName = managerName.substring(indexofManager + 13, managerLength);
                var indexOffalse = managerName.indexOf("false");
                managerName = managerName.substring(0, indexOffalse);
            }
        });
        alert(managerName);
       
});

 UserProfile_GUID

- AccountName

- FirstName

- LastName

- PreferredName

- WorkPhone

- Office

- Department

- Title

- Manager

- AboutMe

- PersonalSpace

- PictureURL

- UserName

- QuickLinks

- WebSite

- PublicSiteRedirect

- SPS-Dotted-line

- SPS-Peers

- SPS-Responsibility

- SPS-Skills

- SPS-PastProjects

- SPS-Interests

- SPS-School

- SPS-SipAddress

- SPS-Birthday

- SPS-MySiteUpgrade

- SPS-DontSuggestList

- SPS-ProxyAddresses

- SPS-HireDate

- SPS-LastColleagueAdded

- SPS-OWAUrl

- SPS-ResourceAccountName

- SPS-MasterAccountName

- Assistant

- WorkEmail

- CellPhone

- Fax

- HomePhone