Edit: This might help with your query statement:
<?php
$query = "INSERT INTO tbl(username,ip,link) VALUES('Brin" . $result['id'] . "'," . $REMOTE_ADDR . ",'http://www.domain.com/sub/start.php?username=Brin'" . $result['id'] . "')";
$results = mysql_query($query) or die('<p>Query failed: ' . mysql_error() . '</p>');
?>
HTH. 😃