Job Tracker Customization

Hello,

I am trying to create a customization on the job tracker that would fire upon input of a new job number. However, I cannot seem to find the proper event type to use. I tested Load, and just utilized a message box, which fired fine. When trying BeforeRowChange and AfterRowChange as well as BeforeFieldChange and AfterFieldChange, I have not been able to get it to fire. Thank in advance for any help!