Health Tool Script?

Why won't this work?

r = script.Parent.Parent.Name

function heal()
	local health = game.Players.r.Humanoid.Health
	health = health+50
	script.Parent.Handle.Sound:play()
	wait(5)
end

script.Parent.Activated:connect(heal)

Please help! Thanks

EDIT: I edited the script according to CreativeEnergy's answer to the following:

r = script.Parent.Parent.Name	 

function heal()
local h = game.Workspace:FindFirstChild(r).Humanoid.Health
h = h+50
script.Parent.Handle.Sound:Play()
end
	 
script.Parent.Activated:connect(heal)

Now the output tells me I'm attempting to index a nil value on line four. Need more help.

This is the 3rd time I've had to retype this answer and I'm on a phone so I will get to the point.

You're trying to find the character in players how you have it now, so we can change line 4 to game.Workspace:FindFirstChild(r).Humanoid.Health

Note: This is in assumption that the characters name is unique in the workspace.

In addition to what CreativeEnergy says:

-You could also use game.Players[r].Character.Humanoid.Health instead of using FindFirstChild

-Since script.Parent.Parent is probably the Player, you could just use a "player" variable.

-You must reference the humanoid and increase its .Health value. At the moment, you're just increasing your local health variable.

-wait(5) does nothing if you don't use "debounce".

Fixed function:

db = false --debounce
function heal()
	if db then return end --prevent multiple instances of the function from running simultaneously
    local humanoid = script.Parent.Parent:FindFirstChild("Humanoid")
	if humanoid == nil then return end
	humanoid.Health = humanoid.Health + 50
    script.Parent.Handle.Sound:play()
	db = true --normally this is put right after the "if db then return end" line, but it's fine so long as we put it before the wait() command. We mustn't let "db" be true if we return early (ex if the humanoid is nil).
	wait(5)
	db = false
end

script.Parent.Activated:connect(heal)