Why does this hat not stay on the players head? And Why wont this face show?

player = game.Players.LocalPlayer
h = player.Character.Head
script.Parent.MouseButton1Down:connect(function()
    if not h.face.Texture == "http://www.roblox.com/asset/?id=138224650" then
    h.face:Destroy()
    for _,v in pairs(player.Character:GetChildren()) do
        if v.ClassName == "Hat" then
            v:Destroy()
            for _,i in pairs(game.ServerStorage:GetChildren()) do
            i:clone().Parent = player.Character
            player.Character:MakeJoints()
            end
        end
    end
    local newface = Instance.new("Decal",h)
    newface.Name = "face"
    newface.Texture = "http://www.roblox.com/asset/?id=138224650"
    end
end)

The hat just falls off and it will not attach to the player. The face becomes blank and it won't change. I want the hat to attach to the player's head when clicked on the gui. What I don't understand is that it does not work. I want the face to change to the custom face that I made. I have tried a local script but I don't know why it won't work

Any help is appreciated ! :D