gistfile1.php

<?php
define('MYACTIVERECORD_CONNECTION_STR', 'mysql://username:password@localhost/databasename');
require_once('MyActiveRecord.php');
class User extends MyActiveRecord{
  //this model will "wrap" a database table named exactly 'user'
  //and having an auto-incrementing primary key named 'id'

  //extend base model methods here
  function save(){
    //mandatory checkbox
    $this->validate_existence('foo','Foo must be checked');
    return parent::save();
  }
}
$id = (isset($_GET['id'])) ? (int) $_GET['id'] : 0;
if($user = MyActiveRecord::FindById('User',$id)){
  //welcome back
}else{
  $user = MyActiveRecord::Create('User');
}
//handle updates
if(isset($_POST['save'])){
  $user->populate($_POST);
  $user->save();
  if(false == $user->get_errors()){
    header('Location: your_form.php?id=' . $user->id); //clear the POST and show the form again
    exit;
  }else{
    die(print_r($user->get_errors(),true); //ugly error message for testing
  }
}
//set global variables
extract(get_object_vars($user));
?>