It does work for me...
Are you trying this in the map script and have you written this line?
local map = ...
If your door is not a door entity but a dynamic tile, try this line
door_to_b1:set_enabled(false)
instead of map:open_doors()
Anyway, this code
if door_leftswitch:on_activated() and door_rightswitch:on_activated() then
door_to_b1:is_opening("true")
end
can't work for the following reasons:
1.) on_activated() is a function that is called when the switch is activated. The function that tells you whether the switch is activated is called is_activated()
2.) is_opening is a function that returns a boolean value and doesn't take any parameters. So this won't have any effect.