Alert方法

    public class ClientScript
    {
        /**//// <summary>
        /// 
        /// </summary>
        /// <param name="message"></param>
        /// <param name="curentPage"></param>
        public static void ShowMessage(string message, Control curentPage)
        {
            ShowMessage(message, curentPage, 0);
        }

        /**//// <summary>
        /// 用弹出对话框显示消息alert("test")
        /// </summary>
        /// <param name="message"></param>
        /// <param name="curentPage"></param>
        /// <param name="messageID">messageID > 0，表示还需要继续显示消息</param>
        public static void ShowMessage(string message, Control curentPage, int messageID)
        {
            //<script language='javascript' type='text/javascript'>alert('保存成功!');window.opener=null;window.close()</script>

            StringBuilder sb = new StringBuilder();
            sb.Append("<script language='javascript' type='text/javascript'>");
            sb.Append("function ShowMessage" + messageID.ToString() + "() {\n");
            sb.Append("var objShowMessage=document.getElementById('showMessage');\n");
            sb.Append("if(objShowMessage) {\n");
            sb.Append("if(objShowMessage.value==1) {\n");
            sb.Append("alert('" + message + "');\n");
            if ( 0 == messageID )
            {
                sb.Append("objShowMessage.value=0;\n");
            }
            sb.Append("}\n");    //if
            sb.Append("}\n");    //if
            sb.Append("}\n");    //function

            sb.Append("window.addOnLoadListener(ShowMessage" + messageID.ToString() +  ");\n");
            sb.Append("</script>");

            Page page = curentPage as Page;
            if (page != null)
            {
                if (!page.ClientScript.IsClientScriptBlockRegistered(page.GetType(), "CLIENT_SCRIPT_SHOW_MESSAGE"))
                {
                    page.ClientScript.RegisterClientScriptBlock(page.GetType(),"CLIENT_SCRIPT_SHOW_MESSAGE" , sb.ToString());
                }
            }
        }
    }

aspx:

  <script>
    function OnWindowLoad()
    {
        for(var i = 0; i < window.onloadListeners.length; i++) {
            var func = window.onloadListeners[i];
            func.call(this);
        }
    }
    window.onloadListeners = new Array();
    window.addOnLoadListener = function(listener) 
    {
        window.onloadListeners[window.onloadListeners.length] = listener;
    }
    window.onload = OnWindowLoad;
    </script>
    <asp:HiddenField runat="server" ID="showMessage" Value="1" />