Can someone tell me how to stop this animation?

I finally did a script on my own, Even though I looked at free models and Forums to see how to put it together But here it is, please tell me how to stop the animation when I press Q again?

LOOK!! I already have the part where when I FIRST press Q The Animation DOES start(although my walkspeed doesnt change).. but when I press Q again IT DOESNT STOP, and my walkspeed doesnt change!! How do I MAKE IT STOP?!

wait(2)

local player = game.Players.LocalPlayer
local Mouse = player:GetMouse()

Mouse.KeyDown:connect(function(key)
if key == "q" then
s = player.Character.Humanoid:LoadAnimation(game.StarterPack.AnimScrip.Animation)
script.Parent.Parent.Parent.Humanoid.Walkspeed = 22
s:Play()
elseif key == "q" then
s = player.Character.Humanoid:LoadAnimation(game.StarterPack.AnimScrip.Animation)
script.Parent.Parent.Parent.Humanoid.Walkspeed = 16
s:Stop()
end
end)

Well, not sure, but i bet this works:

wait(1)

local player = game.Players.LocalPlayer
local isP = false
local Mouse = player:GetMouse()

Mouse.KeyDown:connect(function(key)
if key == "q" then
       if(isP==false)then isP=true
       local s = player.Character.Humanoid:LoadAnimation(game.StarterPack.LocalScript.Animation)
       s:Play() 
       else isP=false
       local s2 = player.Character.Humanoid:LoadAnimation(0)
       s2:Play()
       end
end
end)

Hope this helps! If not, tell output...

You should search thoroughly though the wiki this website and other resources before asking a question here, it took me 2 minutes to find a similar question, of similar nature here.

Try this:

local player = game.Players.LocalPlayer
local Mouse = player:GetMouse()
 s = player.Character.Humanoid:LoadAnimation(game.StarterPack.LocalScript.Animation) -- Define here

Mouse.KeyDown:connect(function(key)
	if key == "q" then -- Needed a tab here
		s:Play()
	end
end)

Mouse.KeyUp:connect(function(key)
	if key == "q" then -- Needed a tab here
		s:Stop()
	end 
end)

Actually, Mystdar made a small mistake on line 13. Try this one:

local player = game.Players.LocalPlayer
local Mouse = player:GetMouse()
 s = player.Character.Humanoid:LoadAnimation(game.StarterPack.LocalScript.Animation) -- Define here

Mouse.KeyDown:connect(function(key)
    if key == "q" then -- Needed a tab here
        s:Play()
    end
end)

Mouse.KeyUp:connect(function(key)
    if key == "q" then -- Needed a tab here
        s:Stop() -- forgot to put () after stop
    end 
end)