<?php
require 'openid.php';
try {
    $openid = new LightOpenID;

$openid->required = array('contact/email');//
$openid->optional = array('namePerson','namePerson/friendly','birthDate','person/gender');//

    if(!$openid->mode) {
            $openid->identity = 'yahoo.com';
            header('Location: ' . $openid->authUrl());
?>
<form action="" method="post">
    <button>Login with Yahoo!</button>
</form>
<?php
    } elseif($openid->mode == 'cancel') {
        echo 'User has canceled authentication!';
    } else {
        echo 'User ' . ($openid->validate() ? $openid->identity . ' has ' : 'has not ') . 'logged in.';
        print_r( $openid->getAttributes());//
    }
} catch(ErrorException $e) {
    echo $e->getMessage();
}