triggers, stored procedures

I am fairly new to Informix, and need to develop a point of sale, order entry, and accounting app. So far, have been using SE engine and isql to set up tables and load data for prototype. Inventory tables will be about 150,000 rows and there will be about 1,000,000 transactions a year. The app will run on SCO unix and should support up to 100 concurrent users. There is nothing in the docs (v4.10 SE, isql) about triggers and stored procedures, but I read that these were available in an Informix programming book. Is this a 4gl thing, an online only thing, or should I be looking for a version upgrade? Also, any thoughts on CASE tools (Appgen etc.) Thanks in advance Brian Finnegan