How come this script wont work?(Lines 12-15) wont work

This is my damage script to my fire ball tool and it works with the damage but when I try to add it so that if the Player kills another person their Exp stat in the leader board raises the damage still works but the Exp stat in leader board doesn't raise. I used the Variable PlayerName to find the name of the Player in the Players Folder so I can access the player

PlayerName = script.Parent.Parent.Parent.Name

function onDamage(Part)
	if Part.Parent:FindFirstChild("Humanoid") ~= nil and Part.Parent.Name ~= "script.Parent.Name" then
		script.Disabled = true
		f = Instance.new("Fire", Part)
		for i = 1,25 do
			f.Size = f.Size +0.25
			Part.Parent.Humanoid.Health = Part.Parent.Humanoid.Health -1
			wait(0.05)
		end
		Part.Parent.Humanoid.Sit = true
		if Part.Parent.Humanoid.Health <= 0 then
			game.Players.PlayerName.leaderstats.Exp = game.Players.PlayerName.leaderstats.Exp +1
			end
		f:remove()
		script.Parent:remove()
	end
	wait(0.025)
end

script.Parent.Touched:connect(onDamage)

Line 4, is the part possibly named script.Parent.Name? If not, remove the quotations and it should work fine. I don't see any other clear errors

game.Players.LocalPlayer.leaderstats.Exp = game.Players.LocalPlayer.leaderstats.Exp +1

On line 5, you disable the script. That's why nothing happens.