placing object on top of other objects

hey guys 

i have an object spawning every 2.9 seconds

but the problem is that it spawns over other display objects

i tried every possibilities that i could but all in vein 

Code :

local composer = require( "composer" ) local widget = require "widget" local scene = composer.newScene() -- ----------------------------------------------------------------------------------- -- Code outside of the scene event functions below will only be executed ONCE unless -- the scene is removed entirely (not recycled) via "composer.removeScene()" -- ----------------------------------------------------------------------------------- local trans\_virus, timer\_virus local button1, button2, button3 local moneybar, keybar, key, moneyText, keyText local backgroundTitle local virus -- ----------------------------------------------------------------------------------- -- Scene event functions -- ----------------------------------------------------------------------------------- local function spawnVirus() virus = display.newImageRect("menuImages/virus.png",100,100) virus.x = math.random(screenLeft + screenWidth \* 0.1, screenRight - screenWidth \* 0.1) virus.y = screenTop - virus.height trans\_virus = transition.to(virus, { y = screenBottom + virus.height , time =3000, onComplete = function (self) display.remove(self); self = nil; print("removed") end }) backgroundTitle:toFront() button1:toFront() button2:toFront() button3:toFront() moneybar:toFront() moneyText:toFront() keybar:toFront() keyText:toFront() key:toFront() end local function onButtonTouch( event ) -- body if (event.phase == "ended") then composer.gotoScene("scene\_"..event.target.name,"crossFade") if virus~= nil then display.remove(virus) virus = nil end if timer\_virus then timer.cancel(timer\_virus) end end end -- create() function scene:create( event ) local sceneGroup = self.view -- Code here runs when the scene is first created but has not yet appeared on screen -- background, music local backgroundImage = display.newImageRect(sceneGroup,"menuImages/image\_background.png",640,1200) backgroundImage.x = centerX backgroundImage.y = centerY backgroundImage.width = screenWidth backgroundImage.height = screenHeight backgroundTitle = display.newText ("Ball Saver",0,0,\_titleFont,200) backgroundTitle.x = centerX backgroundTitle.y = screenHeight \* 0.2 if user.playSound == true then audio.setVolume(1) else audio.setVolume(0) end --buttons button1 = widget.newButton { width = 400 , height = 100 , defaultFile = "menuImages/button1.png", overFile = "menuImages/button1\_over.png", font = \_font, fontSize = 55 , label = "Play", labelColor = { default = {1,1,1} , over = {1,0.9,1} }, onEvent = onButtonTouch } button1.x = centerX button1.y = centerY button1.name = "play" button2 = widget.newButton { width = 400 , height = 100 , defaultFile = "menuImages/button2.png", overFile = "menuImages/button2\_over.png", font = \_font, fontSize = 55 , label = "Upgrades", labelColor = { default = {1,1,1} , over = {1,0.9,1} }, onEvent = onButtonTouch } button2.x = centerX button2.y = button1.y + button1.width \* 0.35 button2.name = "upgrades" button3 = widget.newButton { width = 400 , height = 100 , defaultFile = "menuImages/button3.png", overFile = "menuImages/button3\_over.png", font = \_font, fontSize = 55 , label = "Options", labelColor = { default = {1,1,1} , over = {1,0.9,1} }, onEvent = onButtonTouch } button3.x = centerX button3.y = button2.y + button2.width \* 0.35 button3.name = "options" -- money moneybar = display.newImageRect(sceneGroup,"menuImages/bar.png",140,50) moneybar.anchorX = 1 moneybar.x = screenRight - 25 moneybar.y = screenTop + moneybar.height moneyText = display.newText(sceneGroup, "$".." "..user.money,0,0,\_font,30) moneyText.anchorX = 1 moneyText.x = moneybar.x - moneybar.width \* 0.1 moneyText.y = moneybar.y -- keys keybar = display.newImageRect(sceneGroup,"menuImages/bar.png",140,50) keybar.anchorX = 1 keybar.anchorY = 0 keybar.x = screenRight - 25 keybar.y = screenTop + keybar.height \* 2 key = display.newImageRect (sceneGroup,"menuImages/ruby.png",40,60) key.anchorX = 0 key.anchorY = 0 key.x = keybar.x - keybar.width \* 0.9 key.y = keybar.y - key.height \* 0.1 keyText = display.newText(sceneGroup, ""..user.keys,0,0,\_font,30) keyText.x = key.x + keybar.width \* 0.5 keyText.y = key.y + key.width \* 0.8 if user.money \> 9999 then moneybar.xScale = 1.1 moneyText.anchorX = 1 moneyText.x = moneybar.x - moneybar.width \* 0.15 end if user.money \> 99999 then moneybar.xScale = 1.3 moneyText.anchorX = 1 moneyText.x = moneybar.x - moneybar.width \* 0.2 end --inserting into sceneGroup sceneGroup:insert(button1) sceneGroup:insert(button2) sceneGroup:insert(button3) sceneGroup:insert(backgroundTitle) print(display.imageSuffix) end -- show() function scene:show( event ) local sceneGroup = self.view local phase = event.phase if ( phase == "will" ) then -- Code here runs when the scene is still off screen (but is about to come on screen) elseif ( phase == "did" ) then -- Code here runs when the scene is entirely on screen --viruses timer\_virus = timer.performWithDelay(2900,spawnVirus,0) end end -- hide() function scene:hide( event ) local sceneGroup = self.view local phase = event.phase if ( phase == "will" ) then -- Code here runs when the scene is on screen (but is about to go off screen) timer.cancel(timer\_virus) elseif ( phase == "did" ) then -- Code here runs immediately after the scene goes entirely off screen end end -- destroy() function scene:destroy( event ) local sceneGroup = self.view -- Code here runs prior to the removal of scene's view end -- ----------------------------------------------------------------------------------- -- Scene event function listeners -- ----------------------------------------------------------------------------------- scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) -- ----------------------------------------------------------------------------------- return scene

local function spawnVirus spawns my object… i wanted all other objects to place over it

it will probably work if you insert it into scene gruop and call toBack()

it will probably work if you insert it into scene gruop and call toBack()