magento user registration programmatically

$customer_email = 'test@testemail.com'; 
$customer_fname = 'test_firstname';    
$customer_lname = 'test_lastname';     
$passwordLength = 10;


$customer = Mage::getModel('customer/customer');
$customer->setWebsiteId(Mage::app()->getWebsite()->getId());
$customer->setEmail($customer_email);
$customer->setFirstname($customer_fname);
$customer->setLastname($customer_lname);
$customer->setPassword(md5());
$customer->save();