Customize End Activity form in MES -.NET - 8.03.407

I am trying to customize the End activity form in MES - not having any luck. I cannot seem to access the txtJob feild (eg txtJob.Value). I am also trying to run a routine when the form loads to check if it's a Setup type activity, but I cannot get the Form.Load event to do anything, and I cannot find a way to see if it's indeed a setup activity. Any Help or Idea's would be appreciated