Reference: Several articles about implementing pause in Javascript_javascript tips

Implementation of Javascript sequential execution:
http://www.cnlei.org/blog/article.asp?id=297

JavaScript series - synchronous or asynchronous:
http://blog.iecn.net/blog/html/do-showone-tid-966.html

Implementation of pause function in Javascript:
http: //blog.csdn.net/snakegod/archive/2004/09/22/112810.aspx

JavaScript Sleep function:
http://blog.csdn.net/ gaooo/archive/2007/02/25/1514096.aspx