Observations

<?php

include 'lib.php';
include 'header.php';

  $username = $_POST['keycode'];
  $partner = $_POST['player'];
  $message = $_POST['message'];

  if ($_SERVER["HTTP_X_FORWARDED_FOR"]) {
    $ip = $_SERVER["HTTP_X_FORWARDED_FOR"];
  } else {
    if ($_SERVER["HTTP_CLIENT_IP"]) {
      $ip = $_SERVER["HTTP_CLIENT_IP"];
    } else {
      $ip = $_SERVER["REMOTE_ADDR"];
    }
  }
//echo ("user=\"$username\"  ip=\"$ip\"  ");
  if (isset($message)) {
    mylog($username, "message for $partner:\"$message\"");
  } else {
    mylog($username, "reading chat");
  }

  if (!checkUser($username, $ip)) {
    echo ("error=not logged in");
  } elseif(!isset($partner)) {
    echo ("error=have to specify partner");
  } else {
    $lock = "chat.$username.$partner";
    lock($lock, 10);
    if (isset($message)) {
      if (!mychat($username, $partner, $message)) {
         echo("error=chat with $partner somehow unavailable&");
      }
    }
    echo("contents=" . getchatcontents($username, $partner));
    unlock($lock);
  }
?>