Use ajax technology test the existence of user AJAX (Asynchronous JavaScript and...

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使用ajax技术检验用户是否存在 AJAX(Asynchronous JavaScript and XML)是多种技术的综合，它使用XHTML和CSS标准化呈现，使用DOM实现动态显示和交互，使用XML和XSTL进行数据交换与处理，使用XMLHttpRequest对象进行异步-Use ajax technology test the existence of user AJAX (Asynchronous JavaScript and XML) is an integrated multi-technology, which uses XHTML and CSS standardization of presentation, use the DOM to achieve dynamic display and interaction, the use of XML and data exchange with XSTL deal with, the use of XMLHttpRequest object for asynchronous