例程说明： 留言本的特点： * 区分是否使用邮件和主页图片，保证留下的都是完整、有效的信息 * 将guest.htm改为default.htm * 新增留言内容长度等合法性检查，避免没内容的留言 * 在程序中增加了更多的注释，方便阅读和使用 * 解决了留言页面宽度不一致的问题 * 改用外部样式表，使得再次改进时更简便 * 回复留言时加上及时颜色效果显示 * 留言中允许包含超级连接，其他Html语法一概无效 * 改进了留言图片和颜色搭配方案，重整后的页面更整洁、清新 * 在写留言页面上预留了广告位 　 -Routine Descr iption: This message features:* distinguish whether to use mail and home page pictures, are left to ensure complete and effective information* guest.htm to check the legality of the new default.htm* Message length, not content to avoid comments in the program* added more notes, easy to read and use* to solve the problem of inconsistent message page width* use an external style sheet, making it more convenient time again* improved color timely reply message when you add* effects show comment is allowed to contain a hyperlink, the other Html syntax is void* improved color pictures and messages with the program, after reforming the page a cleaner, fresh* write a message on the page reserved for advertising