How do I make an effect stop when the object is not being touched?

local dealdamage = false

script.Parent.Touched:connect(function(hit)
    if hit.Parent:FindFirstChild("Humanoid") and not dealdamage then
        dealdamage = true
        while hit.Parent.Humanoid do
        if dealdamage then
             hit.Parent.Humanoid.Health = hit.Parent.Humanoid.Health - 1
        else
            break;
        end
            wait()
        end
    end
end)

script.Parent.TouchEnded:connect(function(hit)
    if hit.Parent:FindFirstChild("Humanoid") then
        dealdamage = false;
    end
end)

Basically this script will deal damage when the player touches the part and then stop dealing damage once the player steps off the part. Also, you might want to think about lowering the damage you're dealing to the player. 1 might kill the player a little fast.