<to_user_info>
    <photo>http://webpage/getstpic.ashx?id=10010008460</photo>
    <lastname>asdasd</lastname>
    <firstname>asdasd</firstname>
    <sisiid>aB06B10253</sisiid>
    <school>aswe</school>
    <program>sw</program>
    <registerNr>89021800</registerNr>
    <phones/>
    <emails/>
    <userStatus> er</userStatus>
    <usertype>1</usertype>
</to_user_info>
[download]

So, does it still work if you add XML::Simple in, without adding in LWP::UserAgent?

Yeah It works

#!/usr/bin/perl


#script to do a borrower enquiry/bring up borrower details etc
#written 20/12/99 by chris@katipo.co.nz


# Copyright 2000-2002 Katipo Communications
# Copyright 2013 BibLibre
#
# This file is part of Koha.
#
# Koha is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# Koha is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Koha; if not, see <http://www.gnu.org/licenses>.

use CGI;
use C4::Auth;
use C4::Output;
use C4::Items;
use C4::Context;
use LWP::Simple;               
#use XML::Simple;
use XML::Parser;
use Data::Dumper;
use C4::Members;
#use LWP::UserAgent;
use C4::Branch qw(GetBranches);
use utf8;




my $input = new CGI;
my $remoteip= $input->remote_host();
my ($template, $loggedinuser, $cookie)
    = get_template_and_user({template_name => "members/addfromsisi.tt"
+,
                 query => $input,
                 type => "intranet",
                 authnotrequired => 0,
                 flagsrequired => {borrowers => 1},
                 });

my $rfid= $input->param('rfid');  
my $op= $input->param('op');

        #  request
        my $ua = LWP::UserAgent->new;
        my $response = $ua->get("https://***************/studentservic
+e/service.asmx/give_to_koha_byStudentCard?cardNR=$rfid&ip=$remoteip")
+;
        my $xml=$response->content;
 
        my $xs = new XML::Simple(keeproot =>0,searchpath => ".",forcea
+rray => 1,);
        my $ref = $xs->XMLin($xml);
        my $firstname=${$ref->{firstname}}[0];
        my $lastname=${$ref->{lastname}}[0];
        my $sisiid=${$ref->{sisiid}}[0];
        my $school=${$ref->{school}}[0];
        my $program=${$ref->{program}}[0];
        my $registerNr=${$ref->{registerNr}}[0];
        my $userStatus=${$ref->{userStatus}}[0];
        my $usertype=${$ref->{usertype}}[0];
        my $photo=${$ref->{photo}}[0];
        my $branch=${$ref->{abbrevm}}[0];
        my $op= $input->param('op');

        # save when op= "save"
        my %newdata;
        if($op eq "save"){
        %newdata =("cardnumber"=>"$rfid",
                 "surname"=>"$lastname",
                 "firstname"=>"$firstname",
                 "initials"=>"$registerNr",
                 "address"=>"$program",
                 "userid"=>"$sisiid",
                 "categorycode"=>'ST',
                 "branchcode"=>'EZS',
                 "password"=>'aaaaaaa'
         );

        my $borrowernumber=&AddMember(%newdata);
        #PutPatronImage('aaaaaaaaa', 'image/jpeg', $imgfile);
        if (defined $borrowernumber) {
                my $q = new CGI;
                print $q->redirect(-uri=>"moremember.pl?borrowernumber
+=$borrowernumber");
               }
        }# save end

$template->param(
    rfid=>$rfid,
    photo=>$photo,
    firstname=>$firstname,
    lastname=>$lastname,
    sisiid=>$sisiid,
    school=>$branch,
    program=>$program,
    registerNr=>$registerNr,
    userStatus=>$userStatus,
    usertype=>$usertype,
    remoteip=>$remoteip,
    op=>$op,
    res=> $imgfile,
);

output_html_with_http_headers $input, $cookie, $template->output;
[download]