make gui draggable

local UserInputService = game:GetService("UserInputService")

local gui = script.Parent

local dragging
local dragInput
local dragStart
local startPos

local function update(input)
 local delta = input.Position - dragStart
 gui.Position = UDim2.new(startPos.X.Scale, startPos.X.Offset + delta.X, startPos.Y.Scale, startPos.Y.Offset + delta.Y)
end

gui.InputBegan:Connect(function(input)
 if input.UserInputType == Enum.UserInputType.MouseButton1 or input.UserInputType == Enum.UserInputType.Touch then
  dragging = true
  dragStart = input.Position
  startPos = gui.Position

  input.Changed:Connect(function()
   if input.UserInputState == Enum.UserInputState.End then
    dragging = false
   end
  end)
 end
end)

gui.InputChanged:Connect(function(input)
 if input.UserInputType == Enum.UserInputType.MouseMovement or input.UserInputType == Enum.UserInputType.Touch then
  dragInput = input
 end
end)

UserInputService.InputChanged:Connect(function(input)
 if input == dragInput and dragging then
  update(input)
 end
end)