<?php
  /* 
   * The following is a very basic login.php
   * because of the risk of MySQL injection
   * and the lack of MD5 encryption in the
   * database this shouldnt be used for a
   * commercial site. This is merely a backbone
   * example.
   */

  // (1) Get the variables from the forms
  // that sent us info VIA post.
  $user = $_POST['user'];
  $pass = $_POST['pass'];

  // (2) Make a mysql database connection
  mysql_connect("localhost", "user", "pass");

  // (2 a) Select the db with the user and pass table in it
  mysql_select_db("users");

  // Query the mysql database and make $query hold our results 
  $query = mysql_query("select * from users where user = '{$user}' and pass='{$pass}'");
 
  // See if any rows were returned, identifying the user and pass as being existant in the db
  if(mysql_num_rows($query) > 0) {
    // Start our session...
    session_start();
 
    // Set our session user
    $_SESSION['user'] = $user;
  }
?>