Functions and Triggers

I need help on creating a sql function that will check four rows in a table based on that check it will update another row on a different table.  I want to use this function in a trigger statement.
Table 1 (Test Type)
id      cat     sub-cat test            status          timestamp
Table 2 (Record)
timestamp       card    comp_date       status
What I am trying to do is when someone enters data in on table 2 the trigger will verifty the record and then look at all records with the same id and card type, then it will determine the status of the test, or in other words it will change the value of status in table 1.
Thanks, 
 
 
 
RAY HUNTER
Automated Test Group
 
ENTERASYS NETWORKS
 
E-mail:       rhunter@enterasys.com
 
www.enterasys.com