diff --git a/chat.php b/chat.php
index faac59e..c2d893f 100644
--- a/chat.php
+++ b/chat.php
@@ -1,5 +1,8 @@
 <?php
 
+require_once './db_connection.php';
+
+require_once './modules/user.mod.php';
 require_once './modules/chat.mod.php';
 
 
@@ -7,10 +10,15 @@ $user_id = $_GET['id'];
 $pass = $_GET['pass'];
 $chat_message = $_GET['text'];
 
+$user = User :: find ($user_id);
+
+if ($user -> pass === $pass)
+  {
+    $chat = new Chat;
 
+    $chat -> user_id = $user_id;
+    $chat -> text = $chat_message;
 
-$chat = new Chat;
-$chat -> user_id = $user_id;
-$chat -> text = $chat_message;
-$chat -> insert ();
+    $chat -> insert ();
+  }
 
diff --git a/db_connection.php b/db_connection.php
new file mode 100644
index 0000000..289f93a
--- /dev/null
+++ b/db_connection.php
@@ -0,0 +1,18 @@
+<?php
+
+$config = include ('./config.php');
+
+$db_host = $config['host'];
+$db_port = $config['port'];
+$db_user = $config['user'];
+$db_pass = $config['pass'];
+
+$__db_connection = new mysqli ($db_host, $db_user, $db_pass, 'goatoh_training',
+                               $db_port);
+
+unset ($config);
+unset ($db_host);
+unset ($db_port);
+unset ($db_user);
+unset ($db_pass);
+
diff --git a/modules/chat.mod.php b/modules/chat.mod.php
index c478338..e73b46f 100644
--- a/modules/chat.mod.php
+++ b/modules/chat.mod.php
@@ -3,29 +3,13 @@
 class
 Chat
 {
-  private $db;
-
-  private $id;
-  var     $user_id;
-  var     $pass;
-
-  function
-  __construct ()
-  {
-    $config = include ('./config.php');
-
-    $db_host = $config['host'];
-    $db_port = $config['port'];
-    $db_user = $config['user'];
-    $db_pass = $config['pass'];
-
-    $this -> db = new mysqli ($db_host, $db_user, $db_pass, 'goatoh_training',
-                              $db_port);
-  }
+  var $id;
+  var $user_id;
+  var $pass;
 
   function
   insert ():
-  void
+  int
   {
     $sql = "
         INSERT INTO
@@ -36,7 +20,8 @@ Chat
             (
               {$this -> user_id},
               '{$this -> text}')";
-    $this -> db -> query ($sql) or die ("db_insert error $sql");
+    $GLOBALS['__db_connection'] -> query ($sql)
+        or die ("db_insert error $sql");
   }
 }
 
diff --git a/modules/user.mod.php b/modules/user.mod.php
index ca998f0..4edb82e 100644
--- a/modules/user.mod.php
+++ b/modules/user.mod.php
@@ -3,25 +3,9 @@
 class
 User
 {
-  private $db;
-
-  private $id;
-  var     $name;
-  var     $pass;
-
-  function
-  __construct ()
-  {
-    $config = include ('./config.php');
-
-    $db_host = $config['host'];
-    $db_port = $config['port'];
-    $db_user = $config['user'];
-    $db_pass = $config['pass'];
-
-    $this -> db = new mysqli ($db_host, $db_user, $db_pass, 'goatoh_training',
-                              $db_port);
-  }
+  var $id;
+  var $name;
+  var $pass;
 
   public static function
   find (
@@ -35,7 +19,8 @@ User
           user
         WHERE
           id = $id";
-    $result = $this -> db -> query ($sql) or die ("db_select error $sql");
+    $result = $GLOBALS['__db_connection'] -> query ($sql)
+        or die ("db_select error $sql");
 
     $row = $this -> db -> fetch_array ($result);