<?PHP

  $s = $HTTP_GET_VARS["key"];

  echo "<?xml version=\"1.0\" encoding=\"UTF-8\" ?> ";
  echo "<callxml version=\"3.0\"> ";
  echo "  <do label=\" $s \"> ";

  if ($somevar == "123") {
    echo "    <say>you pressed 123 </say> ";
  } else {
    echo "    <say>you pressed another key.</say> ";
  }

  echo "  </do> ";
  echo "</callxml>";

?>