How do I make a block change your walk speed when you click it?

I am not in anyway a good scripter. I just copy and paste and hope to beyond that it works. For the past hour, I've been searching for hours and hours if there was a script to help me with this, but I couldn't find one. I was just wondering if any of you could help me with this. Thanks.

-- insert a click detector into your part
workspace.block.ClickDetector.MouseClick:Connect(function(player) -- replace block with the part
	local char = player.Character or player.CharacterAdded:Wait()
	local hum = char:WaitForChild("Humanoid")
	hum.WalkSpeed = -- put your desired walkspeed here
end)