i making this script but it wont show in leaderboard how do i fix this?

function OnLevelUP(xp,nxp,mgrass,rank,cash)
    if xp.Value >= nxp.Value then
       mgrass = mgrass +5
       rank = rank +1
       cash = cash +20 +rank.Value+20
       nxp = nxp +20
end end
(game.Players.PlayerAdded:connect(function(player)
    local leaderstats = Instance.new("Model")
    leaderstats.Name = "leaderborad"
    leaderstats.Parent = player
    local grass = Instance.new("IntValue")
    grass.Name = "Grass"
    grass.Value = 0
    grass.Parent = leaderstats
    local mgrass = Instance.new("IntValue")
    mgrass.Name = "MaxGrass"
    mgrass.Value = 20
    mgrass.Parent = leaderstats
    local money = Instance.new("IntValue")
    money.Name = "Cash"
    money.Value = 10
    money.Parent = leaderstats
    local xp = Instance.new("IntValue")
    xp.Name = "XP"
    xp.Value = 21
    xp.Parent = leaderstats
    local nxp = Instance.new("IntValue")
    nxp.Name = "NXP"
    nxp.Value = 20
    nxp.Parent = leaderstats
    local rank = Instance.new("IntValue")
    rank.Name = "Rank"
    rank.Value = 1
    rank.Parent = leaderstats
xp.Changed:connect(function()OnLevelUP(xp,nxp,mgrass,rank,cash)
end)end

Here a Error Script