http status 500具体错误请教 - 编程论坛

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: /Test6.jsp(9,5) Invalid standard action
    org.apache.(DefaultErrorHandler.java:40)
    org.apache.(ErrorDispatcher.java:407)
    org.apache.(ErrorDispatcher.java:88)
    org.apache.(Parser.java:1172)
    org.apache.(Parser.java:1461)
    org.apache.(Parser.java:137)
    org.apache.(ParserController.java:255)
    org.apache.(ParserController.java:103)
    org.apache.(Compiler.java:170)
    org.apache.(Compiler.java:332)
    org.apache.(Compiler.java:312)
    org.apache.(Compiler.java:299)
    org.apache.jasper.(JspCompilationContext.java:586)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.20 logs

刚看了各位高手对http500的错误解释，但是根据意见修改后还是不对，所以把错误和代码写出来请各位指教
以下是源代码

<%@ page language="java" contentType="text/html; charset=gb2312"%>
<html>
<head>
<title>jsp动作</title>
</head>
<body>
<jsp:useBean id = "jb" scope = "session" class = "JSP.Bean1"/>
属性sample的原有值
<jsp:getproperty property="jb" name="sample"/>
<jsp:setProperty property="jb" name="*"/>
<form method = "post">
输入新的值<input name = "sample"/>
<P></P>
<input type = "submit" name = "submit" value = "submit"/>
<input type = "reset" name = "reset" value = "reset"/>
属性当前值
<jsp:getProperty property="jb" name="sample"/>
</form>
</body>
</html>

package JSP;

public class Bean1 {
private String sample = "";
public String getSample(){
    return sample;
}
public void setSample(String newValue){
        sample = newValue;
}
}