if (event == "MOUSE_BUTTON_PRESSED" and arg == 4) then
recoil = not recoil
OutputLogMessage("recoil = %s\n",recoil)
end
--当按下4号键时，改变开关变量（切换开关状态）
源代码如上 诉求是按下4号键开启 按1、2、3键是关闭 球球了

不清楚recoil 含义，最好全点的代码贴下，自己调调看
if (event == "MOUSE_BUTTON_PRESSED" and arg == 4) then
recoil = not recoil
OutputLogMessage("recoil = %s\n",recoil)
elseif (event == "MOUSE_BUTTON_PRESSED" and
(arg == 1 or arg == 2 or arg == 3) )then
OutputLogMessage("recoil = %s\n",recoil)
end