【入门夯实】Lua tonumber：祖玛教主报名金元的输入校验

local function signUp(actor, input)
    if input >= 20000 then              -- 字符串比数字，直接报错
        takeitem(actor, "金元", input)  -- 数量为字符串，同样非法
        beginteleport(actor, 3, 331, 333)
    end
end

local function signUp(actor, input)
    local fee = tonumber(input)
    if not fee or fee < 20000 then
        sendmsg(actor, 1, "需上交 20000 金元")
        return
    end
    takeitem(actor, "金元", fee)
    beginteleport(actor, 3, 331, 333)
    sendmsg(actor, 1, "报名成功，传送祖玛阁")
end