When you install an agent for the first time, a window that contains a script template is opened. The script template is text that contains skeleton code for the four events that can be monitored; see The Four Default Event Routines.
Clicking Edit Script in the New Agent dialog box starts Microsoft Notepad as your script editor. At this point, you can either code your script's actions directly, or delete the template code, copy code from another source (such as the LitCrit_Agent.asp file for the LitCrit application), and paste the new code into the scripting window. When you exit this window, the script is saved into a hidden file in the folder to be monitored.
The Installing the LitCrit Event Service Agent procedure walks you through the steps of opening the script window and copying the LitCrit agent script into it.