What do I have wrong? I need some help!

I am trying to make a Hunger Game's countdown script, What's supposed to happen is that when I say the command, (Only certain people can, just like a holo brick used for doors in wargroup places)there would be a BilboardGUI that turns on when the command is said, and does a countdown (Decals, not text) with a sound that plays for 1 second, for ten seconds, there is a hint on the top of the screen that welcomes the players before the countdown starts, and when the countdown ends, while they tell you the numbers the countdown it's at, the bilboardgui disables itself afterwards, and the command can be run again. Can anybody help? I don't see the errors.

Tree: Workspace Countdown Script Music Brick BillboardGui ImageLabel

~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~

local sound = script.Music
local waitingTime = script.Music.TimeLength

local cd10 = "http://www.roblox.com/asset/?id=322217722"
local cd9 = "http://www.roblox.com/asset/?id=322217742"
local cd8 = "http://www.roblox.com/asset/?id=322217773"
local cd7 = "http://www.roblox.com/asset/?id=322217789"
local cd6 = "http://www.roblox.com/asset/?id=322217805"
local cd5 = "http://www.roblox.com/asset/?id=322217825"
local cd4 = "http://www.roblox.com/asset/?id=322217848"
local cd3 = "http://www.roblox.com/asset/?id=322217906"
local cd2 = "http://www.roblox.com/asset/?id=322217906"
local cd1 = "http://www.roblox.com/asset/?id=322217967"

admins == {"EternaAurora","Duskriser","Player","Player1"} --Admin names here



------------------------------------------------------------------------------------------------------------------------




function isAdmin(name) 
        for i,v in pairs(admins) do 
            if name:lower() == v:lower() then return true end
        end 
    return false 
end 


local countdownGui=script.Parent.BillboardGui
    game.Players.PlayerAdded:connect(function(p) 
    if isAdmin(p.Name) then 
        p.Chatted:connect(function(msg) 


        if msg == ":start countdown" then
            --
            script.Parent.BillboardGui.ImageLabel.Visible = true
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd10
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd9
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd8
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd7
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd6
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd5
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd4
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd3
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd2
            wait (waitingTime)
            --
            sound.Play()
            script.Parent.BillboardGui.ImageLabel.Image = cd1
            wait (waitingTime)
            --
            script.Parent.BillboardGui.ImageLabel.Visible = false

        end 


end) 
end 
end)