Getting input of brush entities

[thatguy]

there is a button on jb_new_summer_v2 that will open the cell doors when shot. I want to be able to check if the button was shot then print something in the console after it is shot. Here's what I have so far, but I have no idea how to check the button's input:
hook.Add( "Think", "Another unique name", function(ply)
for k,v in pairs(ents.GetAll()) do
if v:GetName() == "cellopen" then

end
end
end )
I tried using Entity:GetKeyValues() to find something but I couldn't find anything.

[DrLuke]

Wrong forum mate: Developing