按例子操作，还是出错——我的第一个JSF

刚接触JSF，但不怎么顺利。原代码如下：<%@page contentType="text/html" pageEncoding="UTF-8"%><%@taglib prefix="f" uri="http://java.sun.com/jsf/core"%>
<%@taglib prefix="h" uri="http://java.sun.com/jsf/html"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
  "http://www.w3.org/TR/html4/loose.dtd"><html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
  </head>
  <body>
      <h2>This is a Test JSP Page!</h2>
    <f:view>
       <h:form>
        <h:outputText value="UserID:"/>
        <h:inputText id="userid"/>
       </h:form>
    </f:view>
   
  </body>
</html>运行后，出现如下错误：HTTP Status 500 -type Status reportmessagedescription The server encountered an internal error () that prevented it from fulfilling this request.
Apache Tomcat/6.0.13如果去掉<f:view></f:view>及之间的内容，则正常。tomcat的logs下的日志文件：manager.2008-05-05:2008-5-5 16:52:46 org.apache.catalina.core.ApplicationContext log
信息: Manager: init: Associated with Deployer 'Catalina:type=Deployer,host=localhost'
2008-5-5 16:52:46 org.apache.catalina.core.ApplicationContext log
信息: Manager: init: Global resources are available
2008-5-5 16:52:46 org.apache.catalina.core.ApplicationContext log
信息: Manager: list: Listing contexts for virtual host 'localhost'
2008-5-5 16:52:46 org.apache.catalina.core.ApplicationContext log
信息: Manager: list: Listing contexts for virtual host 'localhost'localhost.2008-05-05:2008-5-5 16:52:43 org.apache.catalina.core.ApplicationContext log
信息: ContextListener: contextInitialized()
2008-5-5 16:52:43 org.apache.catalina.core.ApplicationContext log
信息: SessionListener: contextInitialized()
2008-5-5 16:52:55 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.RuntimeException: Cannot find FacesContext
     at javax.faces.webapp.UIComponentClassicTagBase.getFacesContext(UIComponentClassicTagBase.java:1797)
     at javax.faces.webapp.UIComponentClassicTagBase.setJspId(UIComponentClassicTagBase.java:1614)
     at org.apache.jsp.jsp.index_jsp._jspx_meth_f_005fview_005f0(index_jsp.java:110)
     at org.apache.jsp.jsp.index_jsp._jspService(index_jsp.java:83)
     at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
     at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
     at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
     at java.lang.Thread.run(Thread.java:619)高手，指教一下呀。