plr = game:service'Players'.LocalPlayer
char = plr.Character
hum = char:FindFirstChildOfClass'Humanoid'
mouse = plr:GetMouse()
on = false

mouse.KeyDown:connect(function(key)
    if key == "n" then
        if not on then
            on = true
        elseif on then
            on = false
        end
    end
end)

while wait() do
    if char then
        hum = char:FindFirstChildOfClass'Humanoid'
    end
    if on then
        hum:ChangeState(11)
    end