thoughts on sessions and members

hey folks, hope the day is treating you well. here's a programming theory/methodology type question for y'all. i am relatively new to programming and very new to object-oriented(ness). suppose i have a site using sessions managed with an object $dog. $dog contains a member object $dog->member and $dog->member contains a memberid $dog->member->memberid. member information (username and encrypted password) are stored in a database. my index file begins require_once("dog.inc"); // this is where the objects get defined session_start(); session_register("dog"); session_register("dog_member_id"); if (!is_object($dog)) $dog = new dog; i can authenticate a user and carry that user along throughout the session within $dog->member. a member can also logout, meaning that $dog->member no longer refers to them. when a member logs out, there is still a session and valid $dog. so, what are the favored ways of allowing folks to auto-login? the approach i've taken is to set a cookie variable $dog_member_id. i assign their memberid to the session variable $dog_member_id and within my index file, i have if (!isset($HTTP_COOKIE_VARS["dog_member_id"])) { if (isset($HTTP_SESSION_VARS["dog_member_id"])) { setcookie("dog_member_id",$dog_member_id); } } then, i can check to see if $HTTP_COOKIE_VARS["dog_member_id"] is set when someone visits my page by having this in my index. if ($HTTP_COOKIE_VARS["dog_member_id"] > 0) $dog->member = new Member($HTTP_COOKIE_VARS["dog_member_id"]); if ((!is_object($dog->member)) || (!$dog->member->is_member())) $dog->member = new Member(-1); whew! i had this all working in an older site not using objects, so i understand the basics of what's going on. i also can get this to work if i check for $HTTP_COOKIE_VARS["dog_member_id"] within my index file. i believe i also had this working at one time by checking for $HTTP_COOKIE_VARS["dog_member_id"] within the dog object constructor, but of course can't get that to work now :) is this a good approach? is it possible (should i want) to make this check within the dog constructor? what are other approaches? thanks everyone, mike -- mike cullerton