Need help restarting an app

I am making an X-Ray app from one of the books i am following and one of the assignments is to create a restart start button and i have no idea how. Any help would be great! Here is my code.

local proceedButton
display.setStatusBar(display.HiddenStatusBar)

local isXcodeSimulator = “Iphone Simulator” == system.getInfo (“model”)

if(isAndroid or isXcodeSimulator) then
    local alert = native.showAlert ( “Information”, “Camera API not avaidable on Android or iOS Simulator.”, {“OK”})
end

local background = display.newRect ( 0, 0, display.contentWidth, display.contentHeight )
background:setFillColor ( .5, 0, 0)

local text = display.newText ( “Tap anywhere to launch Camera”, 0, 0, nil, 16 )
text:setFillColor ( 1, 1, 1)
text.x = 0.5 * display.contentWidth
text.y = 0.5 * display.contentHeight

local function processing( event )
    proceedButton.alpha = 0
    local scanbar = display.newImageRect (“scan.png”, 320, 50)
    scanbar.x = display.contentWidth/2
    scanbar.y = 0
    transition.to (scanbar, {y=display.contentHeight, time= 2000})
    local skeleton = display.newImageRect (“invertskele.png”, 302, 480)
    skeleton.alpha = 0
    skeleton.x = display.contentWidth/2
    skeleton.y = display.contentHeight/2
    transition.to (image, {alpha = 0, tiem = 4000})
    transition.to (skeleton, {alpha=1, time=5000})
end

local function sessionComplete( event )
    image = event.target
    print ( “Camera”, ( image and “returned an image”) or “session was canceled”)
    print( "sessionComplete: " … session.Complete)
    print( "trget: " … tostring(image))

    if image then
        image.x = display.contentWidth/2
        image.y = display.contentHeight/2
        local w = image.width
        local h = image.height
        print ( "w, h = "…w … “,” … h )
        proceedButton = display.newImage (“button.png”)
        proceedButton.x = 160
        proceedButton.y = 340
        proceedButton:addEventListener ( “tap”, listener )
        background:setFillColor (0,0,0)
        background:removeSelf ()
        text:removeSelf ()
    end
end

local listener = function ( event )
    media.show (media.Camera, sessionComplete)
    return true
end

background:addEventListener ( “tap”, listener )