What's wrong in my script which giving decal on torso?

Hello! I made script which giving decal on torso when you gonna click brick, but it's not working any ideas what's wrong?

This is this script

local brick = script.Parent
local decal = brick:findFirstChild("Decal")

script.Parent.ClickDetector.MouseClick:connect(function(player)
	local humanoid = player.Parent:findFirstChild("Humanoid")
	local torso = player.Parent:findFirstChild("Torso")
	if torso ~= nil and humanoid ~= nil then
		local shirt = player.Parent:findFirstChild("Shirt Graphic")
		if shirt ~= nil then
			shirt.Graphic = decal.Texture
		else
			local altshirt = torso:findFirstChild("roblox")
			if altshirt ~= nil then
				altshirt.Texture = decal.Texture
			else
				print("Torso found. Shirt not found. Assumed to be a robot.")
			end
		end
	else
		print("Not a valid person! T-Shirt cannot be changed!")
	end
end)