if(strpos($username, '@') !==false &&($users=get_user_by_email($username))) $user
register_error($error)
Display an error on next page load.
system_message($message)
Display a system message on next page load.
forward($location="", $reason='system')
Forward to $location.
elgg_echo($message_key, $args=array(), $language="")
Given a message key, returns an appropriately translated full-text string.
get_user_by_email($email)
Get an array of users from an email address.
get_user_by_username($username)
Get user by username.
send_new_password_request($user_guid)
Generate and send a password request email to a given user's registered email address.