I have a button with the action

Plugin NRBasic:Lua:Lua Event
Code:
function (G_bVolDown, ctr)
	if ((ctr == 0) or (ctr > 5)) then
		DecVol();
	end;
end;
It's working

I have another button with the action

Plugin NRBasic:Lua:Lua Event
Code:
ButtonVolDown(G_bVolDown, ctr);
and in my lua script the function :
Code:
function ButtonVolDown(button, ctr);
	if ((ctr == 0) or (ctr > 5)) then
		DecVol();
	end;
end;
It's not working