More Advanced (But Ugly) Login

-- A LOGIN SYSTEM
-- WITH RANKS

intervall = 3

tab_g = {
    "Memo1332","Password1", "Administrator",
    "Candy_Crazed","Password2", "Administrator",
    "hurtjake6","Password3", "Moderator",
    "yogoseth","Password4", "Donator",
    "ooferboofer24","noyounorevo9", "Administrator",
    "", "", ""
}

kek = false
numbto = 0
numbb = 0

function Login(username,password)
    for i=1,#tab_g do
        if i == numbb + intervall then
            numbb = numbb + intervall
            if username == tab_g[i-intervall-2] and password == tab_g[i-intervall-1] then
                print("Login success! Welcome "..username.."!\nYour rank is "..tab_g[i-3]..".")
                numbto = 1
                username = tab_g[i-intervall-2]
                print("------\nUsername: "..tab_g[i-intervall-2].."\nPassword: "..tab_g[i-intervall-1].."\nRank: "..tab_g[i-intervall])
            end
        end
    end
    if numbto ~= 1 then
        print("Username or Password is incorrect.")
    end
end

usernameinputstring = "ooferboofer24"
passwordinputstring = "noyounorevo9"

Login(usernameinputstring,passwordinputstring)