How to control animation in scene window in edit mode?

Sorry for my poor english. I can edit the process in editor but it dosen't refresh the scene window. I tried this but it didn't work in edit mode:

 using UnityEngine;
 
 using UnityEditor;
 
 using System.Collections;
 
  
 
 [CustomEditor(typeof(Animation))]
 
 [ExecuteInEditMode]
 
 public class AnimaViewer : Editor {
 
  
 
  
 
     protected Animation anima;
 
     
 
  
 
     public override void OnInspectorGUI() {
 
         base.OnInspectorGUI ();
 
  
 
         anima = (Animation) target;
 
         this.frame = EditorGUILayout.Slider ("process",frame,0,1);
 
     }
 
  
 
     protected float mFrame;
 
  
 
     float frame{
 
         set{
 
             mFrame = value;
 
             if (anima == null) {
 
                 anima = (Animation)target;
 
             }
 
             anima [anima.clip.name].normalizedTime = frame; // don't work while not play game
 
         }
 
         get{
 
             return mFrame;
 
         }
 
     }
 
 }