Random Player Chooser [Help] + I need a clock?

So I got this, but it seems to crash my ROBLOX Studio when I test it. I also need to figure out how to add a Timer Gui to it. I dragged my timer Gui into the script but it doesn't show up when a random players are chosen how would I add it?

pos1 = 8, 0.59, 14.5
pos2 = -15, 0.59, 14.5 -- The position that the random player will be moved to.
WaitTime = 10 -- The time in-between each player getting picked.
-- DO NOT EDIT ANYTHING BELOW!!! --
-----------------------------------------------------------------------
dft = {}

function GetPlayers()
local c = game.Players:GetChildren()
for i = 1, #c do
table.insert(dft, c[i].Name)
end
end

function Randomize()
GetPlayers()
local d = math.random(1, #dft)
local s = d
local rndm = game.Players:FindFirstChild(dft[s])
if (rndm ~= nil) then
local Player = rndm.Character
Player:MoveTo(Vector3.new(8, 0.59, 14.5))
Player:MoveTo(Vector3.new(-15, 0.59, 14.5))
end
end

while true do
Spawn(wait);wait(50)
Randomize()
end