Time trial

Within the comments of “what’s not working” in this script, I can’t figure out why it wont work. Basically I want this to happen:
If the registered users access_type_id # is 14 it checks the date_added row which holds the time that they registered on the site, then adds 3 minutes to it, and if that time is >= the current time, then update their access_type_id to 1 then send them off to another page. Here I have google just for a test. Any ideas? I’m trying to have people register to the site for free and have an all access pass for 7 days. The time stamp is only set to 3 minutes right now for testing purposes. But nothing is working. The page just displays as normal, with not access_type_id #'s updating in mysql and no redirecting to google.
Please someone, anyone got an idea?

if(!isauthed_fivestar(array('plat_user', 'season_user'), $HTTP_COOKIE_VARS, false)){ // only plat users
	$plat_user = false;
	# check to see that they have some access
	isauthed_fivestar(array('reg_user', 'plat_user', 'season_user'), $HTTP_COOKIE_VARS);
	$plat_user = true; // week user
$username = $HTTP_COOKIE_VARS['log']['username'];
$db_conn = five_connect_db();
# here is what's not working
if($row['access_type_id'] == 14){
if(($row['date_added']+=(60*3)) >= time()){
mysql_query("UPDATE 'registered_mem' SET('access_type_id'='1') WHERE 'username'='$username'",db_conn);
header("location: http://www.google.com");
$type = "trial";
}}#end what's not working
$arr = pull_content_dailyplay($db_conn);