function twitter() {

$link = mysql_connect('localhost', 'DBUSER', 'DBPASS');
mysql_select_db('DBNAME', $link);

$filename = "twitter.txt";
$handle = fopen($filename, "r");
$last_id = fread($handle, filesize($filename));
fclose($handle);

$xml_file = "http://twitter.com/statuses/public_timeline.xml";

if(!empty($last_id)) {
    $xml_file .= '?since_id='.$last_id;
}

$xml = simplexml_load_file($xml_file);
$c=1;
$res = array();
foreach($xml->status as $status) {
    if($c == 1) {
        $filename = "twitter.txt";
        $handle = fopen($filename, "w");
        fwrite($handle, $status->id);
        fclose($handle);
    }
    $n = strip_tags($status->source);
    $q = "SELECT id, count FROM services WHERE service = '".strip_tags($status->source)."'";
    $query = mysql_query($q);
    if($row = @mysql_fetch_array($query)) {
        $res[$n]['count'] = $row['count'];
        $res[$n]['add_to_count'] = $res[$n]['add_to_count'] + 1;    
        $res[$n]['new_count'] = $res[$n]['count'] + $res[$n]['add_to_count'];
        $res[$n]['query'] = "UPDATE services SET count='".$res[$n]['new_count']."' WHERE service = '".$n."'";
    } else {
        $res[$n]['count'] = 0;
        $res[$n]['add_to_count'] = $res[$n]['add_to_count'] + 1;    
        $res[$n]['new_count'] = $res[$n]['count'] + $res[$n]['add_to_count'];
        $res[$n]['query'] = "INSERT INTO services VALUES('', '".$n."', '".$res[$n]['new_count']."')";
    }           
    $c++;
}

foreach($res as $s) {
    mysql_query($s['query']);
}

mysql_close($link);
}