I'm trying to use this function : GUIStyle.DrawWithTextSelection

void OnGUI ()
    {
       text = new GUIContent ("I want select this part by code");
       if (Event.current.type == EventType.Repaint) {
         myLabelID = GUIUtility.GetControlID (text, FocusType.Keyboard, rect);
         GUI.skin.GetStyle ("MyLabel").DrawWithTextSelection (rect, text, myLabelID, 5, 10);
       }
    }

It draw my text, but with no selection. What i missed ? :(