How do I make the mouse move freely when a GUI pops up?

I've been looking for what to do. So I had an idea:

Create a BoolValue in the GUI called "PopUp" When your GUI appears, leave PopUp true. After the GUI disappears, leave PopUp false.

You should only add the GUI name in the script. If you need more than 1 GUI to move the mouse tell me in comments. i will try to fix for more than 1 GUI.

Fixed script:

wait(2)

local ValueLocation = script.Parent -- Find PlayerGui/Location of all GUI's
local ValueName = "PopUp"

if ValueLocation:FindFirstChild(ValueName) then
	print("Already have a instance.")
else
	local instance = Instance.new("BoolValue", ValueLocation)
	instance.Name = ValueName
	print("Instance created! if you set this value to true. can move mouse! ( INFO: Instance Name" .. tostring(ValueName) .. " Instance Parent: " .. tostring(ValueLocation.Name) .. " )")
end

local InputService=game:GetService("UserInputService")
local Camera=game.Workspace.CurrentCamera
local Player=game.Players.LocalPlayer
local Character=Player.Character
local Head=Character.Head
local Torso=Character.Torso
local RootPart=Character.HumanoidRootPart
local RootJoint=RootPart.RootJoint
local Neck=Torso.Neck
Camera.FieldOfView=90
Camera.CameraType="Scriptable"
InputService.MouseBehavior = Enum.MouseBehavior.LockCenter



local v3=Vector3.new
local cf=CFrame.new
local components=cf().components
local inverse=cf().inverse
local fromAxisAngle=CFrame.fromAxisAngle
local atan,atan2=math.atan,math.atan2
local acos=math.acos

local function toAxisAngleFromVector(v)
    local z=v.z
    return z*z<0.99999 and v3(v.y,-v.x,0).unit*acos(-z) or v3()
end

local function AxisAngleLookOrientation(c,v,t)--CFrame,Vector,Tween
    local c=c-c.p
    local rv=(inverse(c)*v).unit
    local rz=rv.z
    return rz*rz<0.99999 and c*fromAxisAngle(v3(rv.y,-rv.x,0),acos(-rz)*(t or 1)) or c
end

local function AxisAngleLookNew(v,t)--CFrame,Vector,Tween
    local rv=v.unit
    local rz=rv.z
    return rz*rz<0.99999 and fromAxisAngle(v3(rv.y,-rv.x,0),acos(-rz)*(t or 1)) or cf()
end

local function AxisAngleLook(c,v,t)--CFrame,Vector,Tween
    local rv=(inverse(c)*v).unit
    local rz=rv.z
    return rz*rz<0.99999 and c*fromAxisAngle(v3(rv.y,-rv.x,0),acos(-rz)*(t or 1)) or c
end

local Sensitivity=0.005
local CameraDirection=Vector3.new(0,0,1)

local function EulerAnglesYX(l)
    local x,z=l.x,l.z
    return atan(l.y/(x*x+z*z)^0.5),-atan2(x,-z)
end

local function AnglesXY(l)
    local z=l.z
    return atan2(l.y,-z),-atan2(l.x,-z)
end

local function MouseMoved(Input)
    if Input.UserInputType==Enum.UserInputType.MouseMovement then
        local dx,dy=Input.Delta.x*Sensitivity,Input.Delta.y*Sensitivity
        local m2=dx*dx+dy*dy
        if m2>0 then
            CameraDirection=(AxisAngleLookOrientation(RootPart.CFrame,CameraDirection)*fromAxisAngle(v3(-dy,-dx,0),m2^0.5)).lookVector
        end
        local RootOrientation=RootPart.CFrame-RootPart.Position
        local RelativeDirection=RootOrientation:inverse()*CameraDirection
        local AngX,AngY=AnglesXY(RelativeDirection)--RootOrientation:inverse()*
        if AngX<-1.57*11/12 then
            local y,z,c,s=RelativeDirection.y,RelativeDirection.z,math.cos(-1.57*11/12-AngX),-math.sin(-1.57*11/12-AngX)
            z,y=z*c-y*s,z*s+y*c
            CameraDirection=RootOrientation*v3(RelativeDirection.x<0 and -(1-y*y-z*z)^0.5 or (1-y*y-z*z)^0.5,y,z)
        elseif AngX>1.57*11/12 then
            local y,z,c,s=RelativeDirection.y,RelativeDirection.z,math.cos(1.57*11/12-AngX),-math.sin(1.57*11/12-AngX)
            z,y=z*c-y*s,z*s+y*c
            CameraDirection=RootOrientation*v3(RelativeDirection.x<0 and -(1-y*y-z*z)^0.5 or (1-y*y-z*z)^0.5,y,z)
        end
    end
end

local Mouse=Player:GetMouse()

local Zoom=-0.5

Mouse.KeyDown:connect(function(k) 
    if k=="e" then  
        Zoom=-0.5
    elseif k=="q" then
        Zoom=-0.5
    end
end)

InputService.InputChanged:connect(MouseMoved)

Neck.C1=cf()

local _
local DirectionBound=3.14159/3
local CurrentAngY=0

local function CameraUpdate()
	    if ValueLocation:FindFirstChild(ValueName).Value == false then
	        if InputService.MouseBehavior ~= Enum.MouseBehavior.LockCenter then
	            InputService.MouseBehavior = Enum.MouseBehavior.LockCenter
	            Character.Humanoid.WalkSpeed = 16
	        end
	        Camera.CameraType="Scriptable"
	        local cx,cz=CameraDirection.x,CameraDirection.z
	        local rvx,rvz=RootPart.Velocity.x,RootPart.Velocity.z
	        if rvx*rvx+rvz*rvz>4 and cx*rvx+cz*rvz<-0.5*(cx*cx+cz*cz)^0.5*(rvx*rvx+rvz*rvz)^0.5 then
	            DirectionBound=math.min(DirectionBound*0.9,math.abs(CurrentAngY*0.9))
	        else
	            DirectionBound=DirectionBound*0.1+3.14159/3*0.9
	        end
	        local AngX,AngY=EulerAnglesYX((RootPart.CFrame-RootPart.Position):inverse()*CameraDirection)
	        if AngY>DirectionBound then
	            RootPart.CFrame=RootPart.CFrame*CFrame.Angles(0,AngY-DirectionBound,0)
	        elseif AngY<-DirectionBound then
	            RootPart.CFrame=RootPart.CFrame*CFrame.Angles(0,AngY+DirectionBound,0)
	        end
	        _,CurrentAngY=EulerAnglesYX((RootPart.CFrame-RootPart.Position):inverse()*CameraDirection)
	        local CameraOrientation=AxisAngleLookNew((RootPart.CFrame-RootPart.Position):inverse()*CameraDirection,1)
	        Neck.C0=CFrame.new(0,1,0)*CameraOrientation*CFrame.new(0,0.5,0)
	        local PreCam=AxisAngleLook(RootPart.CFrame*cf(0,1,0),RootPart.CFrame*v3(0,1,0)+CameraDirection)*CFrame.new(0,0.825,0)
	        if Zoom==8 then
	            local Part,Position=workspace:findPartOnRay(Ray.new(PreCam.p,PreCam.lookVector*-8),Character)
	             Camera.CoordinateFrame=PreCam*CFrame.new(0,0,(Position-PreCam.p).magnitude)
	        else
	            Camera.CoordinateFrame=PreCam*CFrame.new(0,0,Zoom)
	        end
	    elseif ValueLocation:FindFirstChild(ValueName).Value == true then
	       InputService.MouseBehavior = Enum.MouseBehavior.Default
	       Character.Humanoid.WalkSpeed = 0
	end
end

game:GetService("RunService").RenderStepped:connect(CameraUpdate)