The p_web.ProcessLink procedure's embed is a very common place to put code.
glo:owner = p_web.GetSessionValue('ownerstring') !You've already stored the ownerstring value in the session at login
NetTalk supports logging to the Windows system log, which you can view with Microsoft's (formerly SysInternal's) DbgView utility.
There are template options to add various debug statements to the log.
The log will also show the thread in use - in one of Bruce's demonstrations he typed into a locator quickly and one thread executing a request for filtered data started before the previous request had finished. This makes for high performance since everything is asynchronous and there's no waiting for another request to complete.
This is a good way to get to know how NetTalk works.
Anything string from a p_web method is always clipped.
Lots of good information about filtering, use of keys, PROP:SQL, locators. NetTalk has some really cool locaters, including the ability to search more than one column at a time.