rapid fire macro

why my macro in game not work
but i test in clicking test it work

EnablePrimaryMouseButtonEvents(true);
function OnEvent(event, arg)
if IsKeyLockOn("numlock" )then
if IsMouseButtonPressed(3)then
repeat
if IsMouseButtonPressed(1) then
repeat
PressMouseButton(1)
Sleep(100)
ReleaseMouseButton(1)
until not IsMouseButtonPressed(1)
end
until not IsMouseButtonPressed(3)
end
end
end

what wrong with my code ?