Add Login Block in Drupal

<?php
//implement hook_menu()

function Users_menu() {
$items['userlogin'] = array(
'title' => t('Login System'),
'page callback' => 'UserLogin_block_view',
'access callback' => TRUE,
);
}

// create block

function UserLogin_block_view($block_name = '')
{
$form = drupal_get_form('user_login_block');
$block = array
(
'content' => $form,
);
return $block;
}

// flush cache

?>