Filtering a parameter

I had a situation where this was needed.

Came up with this:

function onFilterList()
	if filterList > 5 then
		filterList = filterList + 8
	end
	zone:setParameter("Filter.ShapeA", filterList)
end
	
filters = {[0] = "LP24", "LP18", "LP12", "LP6", "BP12", "BP24", "BR12", "BR24"}
defineParameter("filterList", nil, 0, filters, onFilterList)