unity3d - how to instantiate UI image in unity2D -

i'm making 2d racing game .... , i'm using ui image in canvas background (road) .my car , enemy cars , have tried instantiate enemy car script attaching script empty gameobject attaching enemy prefab enemycar image in script...but strange thing :the enemycar instantiated in hierarchy can't see in game wrong ? wrong related child , parent or ? , how can make ui image child of canvas in script ?

 using unityengine;  using unityengine.ui;  public class generate : monobehaviour  {  public image enemycar;   // use initialization  void start()  {      invokerepeating("createenemy", 1f, 1.5f);  }   void createenemy()  {      instantiate(enemycar);  } } 

in new ui system ui elements can seen if children canvas. instantiating element puts in hierarchy not under canvas. need find reference canvas in seen , set transform parent instantiated enemy. example use c# code.

var _quitmessage = instantiate(resources.load("messages/quitmessage", typeof(gameobject))) gameobject;                 canvasobject = gameobject.find("canvas");                 _quitmessage.name = "quit message";                 _quitmessage.transform.setparent(canvasobject.transform, false);