What's the scenario? What is it that you are executing?
FM can not return the result of what you are executing if that is what you are after.
If you are executing something from the command line you can pipe the result to a text file and then import that...
If you're looking for native filemaker errors returned from your Send Event script step, the best way to check what it will return is to force an error on purpose, and watch it with the Script Debugger in filemaker advanced.
If you can anticipate all of your error situations from Send Event, then you can trap for them using Get(LastError) and turning error capture on before the Send Event.
Of course what Wim said is also true, Send Event does not return errors from your executed event content, but you can read that from a log file if you save the result as part of your event.
Thanks Wim and Mike...
I used Send Event to execute line command.
It works well except native FM script can't capture error.
Now, I employed BaseElements plugins and works seemlessly.
All the best