This script doesnt work when I reset?

Any idea how to fix this?

Here is my code:

local player = game.Players.LocalPlayer
local mouse = player:GetMouse()

repeat wait() until player.Character
local character = player.Character

local selection = Instance.new("SelectionBox",player.PlayerGui)
selection.Color = BrickColor.new("Medium stone grey")

local character = player.Character

local valid_target = character.valid_target

mouse.Icon = "http://www.roblox.com/asset/?id=184642130"
mouse.Move:connect(function()
    local target = mouse.Target
    if target ~= nil then
        local hum = target.Parent:FindFirstChild("Humanoid")
        local enemy = target.Parent:FindFirstChild("enemy")
        local player = target.Parent:FindFirstChild("player")
        local book = target.Parent:FindFirstChild("book")
        local friend = target.Parent:FindFirstChild("friend")
        if hum and target.Parent:IsA("Model") and not player and enemy then
            mouse.Icon = "http://www.roblox.com/asset/?id=165194824"
            selection.Adornee = target.Parent
            valid_target.Value = true
        elseif hum and target.Parent:IsA("Model") and not player and book then
            mouse.Icon = "http://www.roblox.com/asset/?id=186747208"
            selection.Adornee = target.Parent
            valid_target.Value = true
        elseif hum and target.Parent:IsA("Model") and not player and friend then
            mouse.Icon = "http://www.roblox.com/asset/?id=186749391"
            selection.Adornee = target.Parent
            valid_target = true
        elseif hum and target.Parnet:IsA("Model") and player then
            mouse.Icon = "http://www.roblox.com/asset/?id=186750107"
            selection.Adornee = target.Parent
            valid_target = true
        else
            mouse.Icon = "http://www.roblox.com/asset/?id=184642130"
            selection.Adornee = nil
        end
    else
        mouse.Icon = "http://www.roblox.com/asset/?id=184642130"
        selection.Adornee = nil
    end
end)