Why is this function going off when it's not being called?

function FindPlr(a, plr)
	local a = false
	for i,v in pairs(game.Players:GetPlayers()) do
		if string.find(string.lower(string.sub(v.Name,1,string.len(plr))),string.lower(plr),1,false) and plr ~= "" then
			a = v.Name
		end
		end
	return a
end
Functions.FindPlr.OnServerInvoke = FindPlr()

It's not being invoked though..........