Creating Session Variables

Is it possible to use the successful login event to read the user table and create a session variable based on another field ?

I want to associate each user with a 'Company' from the users table and then filter the records they can see based on this.

Er - OK, I discovered it by trial and error.
I added this to the AfterSuccessfulLogin event:

$_SESSION["Company"]=@$data["Company"];

1. For the Add Page:-
   
   I added this to the lookup WHERE clause:
   
   " Company like '".$_SESSION["Company"]."%'"
   and this to the default value for the field:
   
   $_SESSION["Company"]
   
2. For the List Page:-
   I added this to the BeforeQueryList event:
   
   $strWhereClause=whereAdd($strWhereClause,"Company LIKE '".$_SESSION["Company"]."%'");