HELP with XML

[chrisguk]

I have been working on a way to trying and retrieve data using the xmlrpc but keep running into formatting issues on the output. Listed below I have included my php code the xml schema and other related info. As you will see I used preg_replace but thinking about it im not sure that the correct solution.

<?php
error_reporting(0);
$auth = $_POST ['auth'];
$user = $_POST ['user'];
$request   = construct_xml($auth, $authuser, $user);
$response  = check_availability($request);
$available = parse_response($response);

if ($available == 0) {
    echo $response = preg_replace('#\s(?=alias:|login:|password:)#', '<br/>', $response);
}
else {
    echo $response = preg_replace('#\s(?=Alias:|Login:|Password:)#', '<br/>', $response);
}



function construct_xml ($auth, $authuser, $user) {
    return <<<XML
<?xml version='1.0' encoding='utf-8' ?>
<rpc module='Email' method='List_Mailboxes' version='1.0'>
    <auth>
        <username>$authuser</username>
        <password>$auth</password>
    </auth>
    <username datatype='username'>$user</username>
</rpc>


XML;
}

function check_availability ($request) {
    $header .= "POST / HTTP/1.0\r\n";
    $header .= "Content-Type: text/xml\r\n";
    $header .= "Content-Length: " . strlen($request) . "\r\n\r\n";

$fp = fsockopen("xmlrpc.******.co.uk", 29***, $errno, $errstr, 30);

if ($fp) {
    fputs ($fp, $header . $request);
    while (!feof($fp)) {
        $response .= fgets($fp, 2316);
    }
    fclose ($fp);

    $pos      = strpos($response, "\r\n\r\n");
    $response = substr($response, $pos + 4);
}

return $response;
}

function parse_response ($xml) {
    $xml = new SimpleXMLElement($xml);

$code = $xml->response['code'];
$text = $xml->response['text'];

if ($code != 0) {
    echo "Error occurred: $text\n";
    exit;
}

return $xml->availability;
}
?>

And here is the response example:

<?xml version="1.0" encoding="utf-8"?>
<rpc request_id="2316">
    <response code="0" text="OK"/>
    <mailbox datatype="list">
        <alias datatype="mailbox_name">qux</alias>
        <login datatype="mailbox_login">qux@baz</login>
        <password datatype="password">2fbAcx6E</password>
    </mailbox>
    <mailbox datatype="list">
        <alias datatype="mailbox_name">quux</alias>
        <login datatype="mailbox_login">quux@baz</login>
        <password datatype="password">iAgw1R8z</password>
    </mailbox>
</rpc>

And this is the schema:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="rpc">
    <xs:complexType>
      <xs:all>
        <xs:element name="auth">
          <xs:complexType>
            <xs:all>
              <xs:element name="username">
                <xs:simpleType>
                  <xs:restriction base="xs:string">
                    <xs:pattern value="[a-zA-Z0-9_\-\.]{1,16}"/>
                  </xs:restriction>
                </xs:simpleType>
              </xs:element>
              <xs:element name="password">
                <xs:simpleType>
                  <xs:restriction base="xs:string">
                    <xs:pattern value="[a-zA-Z0-9_\-\.\?\!\@\$\(\)]{5,16}"/>
                  </xs:restriction>
                </xs:simpleType>
              </xs:element>
            </xs:all>
          </xs:complexType>
        </xs:element>
        <xs:element name="validate_only" minOccurs="0" maxOccurs="1">
          <xs:complexType>
            <xs:simpleContent>
              <xs:extension base="xs:boolean">
                <xs:attribute name="datatype">
                  <xs:simpleType>
                    <xs:restriction base="xs:string">
                      <xs:pattern value="bool"/>
                    </xs:restriction>
                  </xs:simpleType>
                </xs:attribute>
              </xs:extension>
            </xs:simpleContent>
          </xs:complexType>
        </xs:element>
        <xs:element name="username" minOccurs="1" maxOccurs="1">
          <xs:complexType>
            <xs:simpleContent>
              <xs:extension base="xs:string">
                <xs:attribute name="datatype">
                  <xs:simpleType>
                    <xs:restriction base="xs:string">
                      <xs:pattern value="username"/>
                    </xs:restriction>
                  </xs:simpleType>
                </xs:attribute>
              </xs:extension>
            </xs:simpleContent>
          </xs:complexType>
        </xs:element>
      </xs:all>
      <xs:attribute name="module" type="xs:string"/>
      <xs:attribute name="version" type="xs:string"/>
      <xs:attribute name="method" type="xs:string"/>
    </xs:complexType>
  </xs:element>
</xs:schema>

Is anyone able to assist with getting the desired output in a nice formatted way. I am new at this and all the php code above I constructed by studying the php.net site so I have no idea if its correct or not.

Thanks in advance