MES Main Menu Customization

Vantage 8.03

I am trying to mimic the characteristics of a MES main menu button.  For example, I am trying to create a button to call a customization of the End Activity screen.  I can create the button and link it to the new form, but I want the button to be disabled if the user is not logged into a job and enabled if they are logged into a job, just like the original End Activity button would work.

I only need this customization on a few terminals.  The rest I need to stay original.

I am somewhat new to customization, so the more detail, the better.

Thank you.