Judy,
There are parameters in the JAS.INI that allow you to enable logging. You will have to stop and start the webserver to enable logging. The logging will be for all users, so it may get a bit tricky. Not a big deal if you are the only person testing, but......
I thought I saw a feature in 8.11 that allowed for individual kernals for each web user. If so (sorry I'm on XE so I don't know much about this), turn on that parameter as well as logging. Then you will be able to track your session like you do with a fattie.
Besides turning on logging on the web client, you may also need to enable it on your logic server as well. One good debugging technique is to try the same transaction on both the web and a thick client. Make sure that when you test the thick client, you are logging into the "J" environment. The big difference between the "J" environment and a regular environment is that your business functions are processed on a logic server. I have seen the same application behave very differently depending on whether I ran it from a thick client or a web client. This is especially true with custom objects. When JDE started pushing the web client, they made some changes to some core objects to call different business functions that were designed for supporting the web or a fat client. If you have a custom object that is calling a old, valid, business function that was not redesigned for the web from your web client, you'll have errors.
The lesson here is this - if you are a customer with Vanilla code, going to the web client (in any release) is not a big deal. If you developed custom objects, or modified a JDE/PeopleSoft/Oracle EnterpriseOne Core object, then you will have to test the web client and possibly retrofit your custom objects to meet the current standards. In case you're wondering, yes, we learned this the hard way and because of that have never embraced the web client in any meaningful way.
Good luck with your implimentation!
Gregg Larkin
JDE System Administrator (CNC) / North America
Praxair, Inc.