Make a switch count variable up or down?

[meanmrgreen]

Im installing a cat door this spring and want to check how many cats are indoor and outdoor.

to do this i want to install a switch on either side of the door so when the inside flap goes up it signals domoticz the variable "Number of cats inside" and give it a +1

when outside flap goes up i want this variable to go -1

Is this possible with domoticz? lua? blockly?

[jkimmel]

Look here:

http://www.domoticz.com/forum/viewtopic ... ts#p118190