求ruby+selenium的教程

ahtest

刚开始学习使用selenium,求高人指导一二。。。
selenium对frame的支持不是很好用。有没有什么方法解决？用过select_frame(ruby下的方法)，选择不了frame,很郁闷！
selenium对ajax的支持是如何？

ahtest

代码：@selenium.select_frame 'mainframe'
信息：
Thu Jul 08 17:21:13 +0800 2010 selenium-client received failure from selenium server:
requested:
        cmd=selectFrame
        1=mainframe
        sessionId=b32dcb9c935b44cb936b282bf51efe8d
received:
        "ERROR: Element mainframe not found"
        called from D:/worksoft/ruby186-26_watir162/lib/ruby/1.8/timeout.rb:56:in `timeout'
Selenium::CommandError: ERROR: Element mainframe not found
        from D:/worksoft/ruby186-26_watir162/lib/ruby/gems/1.8/gems/selenium-client-1.2.18/lib/selenium/client/protocol.rb:13:in `remote_control_command'
        from D:/worksoft/ruby186-26_watir162/lib/ruby/1.8/timeout.rb:56:in `timeout'
        from D:/worksoft/ruby186-26_watir162/lib/ruby/1.8/timeout.rb:76:in `timeout'
        from D:/worksoft/ruby186-26_watir162/lib/ruby/gems/1.8/gems/selenium-client-1.2.18/lib/selenium/client/protocol.rb:11:in `remote_control_command'
        from D:/worksoft/ruby186-26_watir162/lib/ruby/gems/1.8/gems/selenium-client-1.2.18/lib/selenium/client/legacy_driver.rb:683:in `select_frame'
        from (irb):35
        from D:/worksoft/ruby186-26_watir162/lib/ruby/1.8/cgi.rb:420