把弹出窗口写成通用方法

 　　　　/// <summary>
        /// 弹出信息
         /// </summary>
        /// <param name="page"></param>
        /// <param name="msg"></param>
        public void showMessage(Control page,string msg)
        {
            string str = "alert('"+msg+"');";
            ScriptManager.RegisterStartupScript(page, Type.GetType("System.String"), str, str, true);
        }