A basic example of using "List Variables" can be found by clicking on the "Examples" button in WinScriptLive.
There are several ways to check for a certain value: the attached an example script that shows 2 different methods.
One just uses simple "if" commands for each -- this is executed very quickly by the show controller.
Another uses a "Loop" method, but this would take several frames to complete since it is "jumping backward" in the sequence. I'm not sure your time requirements for your check.
Yet another way would be to use an integer array (of just size 2), and then reference individual bits rather than using a bool array.