Trying to find cursors distance to the players position

[PirzolaTM (Guardian)]

Hello, i am trying to make a grappling hook, and i have managed to get everything working except for one thing, i cannot figure out how far away the cursor is from the player in the 3D space. How can i set a range to my grappling hook?

Here’s my script

script.GrappleOn.OnServerEvent:Connect(function(player, mousepos, grappling)
	if grappling == false then 
		--print("grappling: " ..tostring(grappling)) --debug
		if player.Character:FindFirstChild("SpringConstraint") then
			player.Character:FindFirstChild("SpringConstraint"):Destroy()
			workspace:FindFirstChild("grapplepart"):Destroy()
		end
		return
	end
	--ref
	local char = player.Character
	local hrp = char.HumanoidRootPart
	-- vector3
	local maxdist = Vector3.new(700, 700,700)
	local dist = mousepos.Magnitude
	--[[ debug
	print(dist)
	print(maxdist)
	print("grappling: " ..tostring(grappling))
	--]]
	if grappling == true then
		if dist <= maxdist.x and dist <= maxdist.y and dist <= maxdist.z then
			local humanoidattachment = Instance.new("Attachment")
			local grapple = Instance.new("SpringConstraint")
			local targetattachment = Instance.new("Attachment")
			local grapplepart = Instance.new("Part")
			local grappleProperties = {
				Thickness = 0.3,
				Coils = 10,
				Parent = char,
				Attachment0 = targetattachment,
				Attachment1 = humanoidattachment,
				Visible = true,
				FreeLength = 2,
				Stiffness = 5000,
				MaxForce = 6500
			}
			local grapplepartProperties = {
				Parent = workspace,
				Anchored = true,
				Position = mousepos,
				CanCollide = false,
				Transparency = 1,
				Name = "grapplepart"
			}
			for x, v in pairs(grappleProperties) do
				grapple[x] = v
			end
			for x, v in pairs(grapplepartProperties) do
				grapplepart[x] = v
			end
			humanoidattachment.Parent = char:FindFirstChild("UpperTorso")
			humanoidattachment.Name = "humanoidattachment"
			targetattachment.Parent = grapplepart
		end
	end
end)

[Ziffixture (Ziffix)]

local distanceAB = (A - B).Magnitude

Where A and B are the two points of interest

[PirzolaTM (Guardian)]

yep, that did it. thank you very much!