http://www.cnlei.org/blog/article.asp?id=297
JavaScript系列-同步还是异步:
http://blog.iecn.net/blog/html/do-showone-tid-966.html
Javascript中暂停功能的实现 :
http://blog.csdn.net/snakegod/archive/2004/09/22/112810.aspx
JavaScript Sleep函数 :
http://blog.csdn.net/gaooo/archive/2007/02/25/1514096.aspx