How To Convert Array To XML On PHP

i have PHP code like this:

public function get_xml_product($serviceName) {
        $product    = Array();
        $idx        = $idx2 = 0;
        $explodeResult=explode(", ",$serviceName);
        foreach($explodeResult as $value)
        {
              $sql = "SELECT id,parent,code,name,xs1 as DOWNLOAD, xs2 as UPLOAD
                       FROM sc_params
                      WHERE rfen = 'SERVICE_REQUESTED'
                      AND code = '".$value."' 
                        OR code IN
                        ( 
                            SELECT code 
                             FROM sc_params 
                             WHERE rfen = 'SERVICE_REQUESTED'
                             AND id = (
                            SELECT parent 
                                 FROM sc_params 
                                 WHERE rfen = 'SERVICE_REQUESTED' 
                                 AND code = '".$value."' )
                        )
                    ";          
            $stmt = oci_parse($this->_conn,$sql);
            $rs = oci_execute($stmt);
            if (!$rs) {
                $error = oci_error();
                $this->_err = $error;
                return false;
            }

            while ($data = oci_fetch_array($stmt, OCI_BOTH)) {
                if($data['PARENT'] == 0) {
                    $idx++;
                    $product[$idx]['id']        = $data['ID'];
                    $product[$idx]['name']      = $data['NAME'];
                }
                else {
                    foreach($product as $product2)
                    {
                    $product[$idx]['download'][$idx2]['name']   = 'DOWNLOAD';
                    $product[$idx]['download'][$idx2]['value'] = $data['DOWNLOAD'];
                    $product[$idx]['upload'][$idx2]['name']   = 'UPLOAD';
                    $product[$idx]['upload'][$idx2]['value'] = $data['UPLOAD'];
                    $idx2++;
                    }
                } 
            }
        }
        print_r($product);
......

the result show:

 Array
    (
        [1] => Array
            (
                [id] => 1
                [name] => INTERNET
                [download] => Array
                    (
                        [0] => Array
                            (
                                [name] => DOWNLOAD
                                [value] => 1024
                            )

                    )

                [upload] => Array
                    (
                        [0] => Array
                            (
                                [name] => UPLOAD
                                [value] => 256
                            )

                    )

            )

and i want to make it into xml like this one:

<xml version="1.0"?>
         <services>
             <service>
                 <id>1</id>
                 <name>INTERNET</name>
                 <attribute>
                     <name>DOWNLOAD</name>
                     <value>1024</value>
                 </attribute>
                 <attribute>
                     <name>UPLOAD</name>
                     <value>512</value>
                 </attribute>
             </service>
</services>

Please Help me....