$user[usergroupid] in showthread.php?

[Isuldor]

I'm trying to write a condition in showthread.php that uses $user[usergroupid] to see what user group the user is in, and if the user is an admin it creates a $post[power] which I've put into the posbit template. Here's what I have so far:

PHP Code:

if ($user[usergroupid]==6) {
  eval("\$post[power] = \"".gettemplate("postbit_admin")."\";");
} 


it's right above

PHP Code:

if ($post[showemail] and $displayemails) { 


(postbit_admin is another template I created) I'm not seeing any results so I'm thinking that I can't use $user because it isn't read from the database in this script, which leaves me with the question: is there another way I can check the persons usergroup in showthread.php?
or am I just plain doing it wrong