Database Trigger simple Code - MSSQL

Hello, Sorry but too many generic bids. To save boths times, i just read bids that start with "I know what a DB trigger is..." ;) THX for your understanding SO- i need a simpel trigger for database. In database there are 2 tables. Table1 is "Transactions" Table 2 is "items" The entries are linked trough one field . In transactions table i want to show up values of items table. I added fields in the transactions table, and I need a code trigger for the transactions table , that on save or update of the entry, the trigger alters the table, it looks up in the items table the corresponding entry (linked via an field) and triggers values from there. I think its clear but can be discussd further. For someone who is familiar with MSSQL (i unfortunately not) this is a 10 minutes job. Need be done today please. Thank you.