public override void OnInspectorGUI()
    {
        ///base.OnInspectorGUI();
        TagsManager tagMgr = (TagsManager)target;

        //////////////////addd
        GUILayout.BeginHorizontal();

        addTagInputField = EditorGUILayout.TextField("Tag Name:", addTagInputField);
        if (GUILayout.Button("Add Tag"))
        {
            addTag(addTagInputField);
        }

        GUILayout.EndHorizontal();

        /////////////////////remove
        GUILayout.BeginHorizontal();

        removeTagInputField = EditorGUILayout.Popup("Tag Index:", removeTagInputField, tagMgr.tags.ToArray());
        if (GUILayout.Button("Remove Tag"))
        {
            tagMgr.removeTag(removeTagInputField);
        }

        GUILayout.EndHorizontal();

        GUIStyle g = new GUIStyle();

        g.alignment = TextAnchor.MiddleCenter;
        g.fontStyle = FontStyle.Bold;
        g.fontSize  = 14;

        EditorGUILayout.LabelField("Tags", g);

        if (tagMgr.tags != null)
        {
            int j = 1;
            for (int i = 0; i < tagMgr.tags.Count; i++)
            {
                if (tagMgr.tags[i] != "undefined")
                {
                    string tmp = EditorGUILayout.TextField("Tag " + (j++) + ":", tagMgr.tags[i]);
                    tagMgr.updateTag(tmp, i);
                }
            }
        }
    }