BilboardGui, If/ElseIf, LabelText, TextButton help?

So, I am expanding on my other question which was answered. I made a script which makes text appear above your head, but then I have made a different script which if the button is pressed, the text above your head changes, but when re-clicked, it changes back.

Original

local function sum(tab)
    local sum = 0
        for _, value in pairs(tab) do
            sum = sum + value
        end
    return sum
end

local function overflow(tab, seed)
    for i, value in ipairs(tab) do
        if seed - value <= 0 then
            return i, seed
        end
        seed = seed - value
    end
end

local InjuryRarity  = {1,3,3,3,3,3,2,1} -- Frequency relative to eachother
local Injuries      = {"Heart Attack", "Chest Pain", "Abdominal Pain", "Broken Leg", "Broken Arm", "Headache", "Toothache", "Foreign Object"}

game.Players.PlayerAdded:connect(function(plr)
    plr.NameDisplayDistance = 0
    plr.CharacterAdded:connect(function(Character)
        -- Get random injury
        local seed          = math.random(1, sum(InjuryRarity))
        local chosenKey     = overflow(InjuryRarity, seed)

        local gui = script.BillboardGui:Clone()
        local id = 2567972

        if plr:GetRankInGroup(id) <= 3 then
            gui.TextLabel.Text = (plr.Name.. ", " .. Injuries[chosenKey])
            gui.Adornee = Character:WaitForChild("Head")
            gui.Parent = Character:WaitForChild("Head")
        elseif plr:GetRankInGroup(id) >= 4 then
            gui.TextLabel.Text = (plr.Name.. ", " .. plr:GetRoleInGroup (id))
            gui.Adornee = Character:WaitForChild("Head")
            gui.Parent = Character:WaitForChild("Head")
        end

    end)
end)

Other Changer

while true do
if script.Parent.NameChanger.Disabled == false
    then
else
    game.Players.PlayerAdded:connect(function(plr)
    plr.NameDisplayDistance = 0
    plr.CharacterAdded:connect(function(Character)
        local gui = script.BillboardGui:Clone()
        local id = 2567972

        if plr:GetRankInGroup(id) <= 3 then
            gui.TextLabel.Text = plr.Name
            gui.Adornee = Character:WaitForChild("Head")
            gui.Parent = Character:WaitForChild("Head")
        elseif plr:GetRankInGroup(id) >= 4 then
            gui.TextLabel.Text = (plr.Name.. ", " .. plr:GetRoleInGroup (id))
            gui.Adornee = Character:WaitForChild("Head")
            gui.Parent = Character:WaitForChild("Head")
        end

    end)
end)
end
end

Button

script.Parent.MouseEnter:connect(function(e)
    local wh = Color3.new(1,1,1)
    local gr = Color3.new(0,1,0)
    local bt = script.Parent
    local cli = script.Sound
    if bt.TextColor3 == gr then
        bt.TextColor3 = wh
        bt.BorderColor3 = wh
        cli:Play()
    end
end)

script.Parent.MouseLeave:connect(function(l)
    local wh = Color3.new(1,1,1)
    local gr = Color3.new(0,1,0)
    local bt = script.Parent
    local cli = script.Sound 
    if bt.TextColor3 == wh then
        bt.TextColor3 = gr
        bt.BorderColor3 = gr
        cli:Play()
    end
end)

function click()
    local sss= game:GetService("ServerScriptStorage")
    if sss.NameChanger.Disabled == false then
        sss.NameChanger.Disabled = true
        sss.NC2.Disabled = false
    else
        sss.NameChanger.Disabled = false
        sss.NC2.Disabled = true 
end
end
local gr = Color3.new(0,1,0)
local bt = script.Parent
bt.TextColor3 = gr
bt.BorderColor3 = gr
end

script.Parent.MouseButton1Down:connect(click)