transaction times - need help

Hi. HP-UX 10.20. OnLine 7.23.UC1. We have an application that historically has been accessed using a GUI on the client pc. Now we are adding front-end access via the web. There is a server in between with an adapter on it. The same stored procedures will get called from the new front-end as were called from the GUI. Some modifications were made to accommodate both front-ends. The people testing the new front-end would like to review performance before we go live. They say that they have ruled out the adapter so now they want to look at whatever else they can. So here's my questions: How can I see how much time a transaction takes in Informix? I know I can take each sql and run it with set explain on to make sure the optimizer is doing it's thing. I could add some date captures in the sql before and after it runs. Is there something from onstat -g ses xx that I could monitor? Any other onstat commands I should use? Anything else? Thanks, Dianne