$a = explode('&', $QUERY_STRING);
$i = 0;
while ($i < count($a)) {
    $b = split('=', $a[$i]);
    echo 'Value for parameter ', htmlspecialchars(urldecode($b[0])),
         ' is ', htmlspecialchars(urldecode($b[1])), "<br />\n";
    $i++;
}