I wanted to start my own Map in LoG2. I´am pretty new at Scripting and the first problems start

I want to make a little Pressureplate puzzle.
For example. Lets say i Have three Plates. Two of them have to be activated and one of them have to be deactivated to open the Door
So in the Editor i place :
3x PressurePlates
1x Door
1x scripting_entity
I connectect the 3x Pressure Plates to scripting_entity and also choose the DoorOpen() function
I renamed the Pressureplates and the Door to make it easyier for me (Plate1,Plate2,Plate3 / Door1)
The scripting_entity looks like:
function DoorOpen()
if Plate1.floortrigger: <<<<<<<<<<< (And here the problem starts) What is the command to let the script check that this plate is active and
Plate2.floortrigger: <<<<<<<<<< same and
Plate3.floortrigger: <<<<<<<<<< same then
Door1.door (dont know if door is right): <<<<<< same
end
end
Hope anyone can help me
