Roblox Double Jump

--To you this script make a local script and put it in starterGUI

--[[
    Put me in StarterGui or StarterPack :)
]]
local Player = game.Players.LocalPlayer
repeat wait() until Player.Character -- Yield until the Player's Character is no longer nil
local Character = Player.Character
local Humanoid = Character:WaitForChild("Humanoid")
local UserInputService = game:GetService("UserInputService")
local currentJump
local debounce = true
local DoubleJumpVelocity = 100 -- 50 is a normal ROBLOX jump

function jumpRayDown()
    local nR = Ray.new(Character.Torso.Position,Vector3.new(0,-1,0).unit*4)
    local hR,pR=game.Workspace:FindPartOnRay(nR,Character)
    if hR~=nil then
        return true
    end
    return false
end

Humanoid.Changed:connect(
    function(Property)
        if Property == "Jump" and debounce == true and Humanoid.Sit==false then
            currentJump=true
            debounce = false
            newConnection = Player:GetMouse().KeyDown:connect(function(key)
                if key:lower():byte()==32 and currentJump and Character.Torso.Velocity.y>-30 then
                    currentJump=false
                    for i, v in pairs(Character:GetChildren()) do
                        if v:isA("BasePart") then
                            v.Velocity = Vector3.new(v.Velocity.x,DoubleJumpVelocity,v.Velocity.z)
                        end
                    end
                end
            end)
            spawn(function()
                repeat wait() until jumpRayDown()==true
                debounce = true
                currentJump = false
                if type(newConnection)=="function" then
                    newConnection:disconnect()
                end
            end)
        elseif Property == "Jump" and Humanoid.Sit==true then
            Humanoid.Jump=false
        end
    end
)