这是login.jsp页面代码:
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.sql.*"%>
<%
 
request.setCharacterEncoding("utf-8");
String No="";
String Name="";
String Lesson="";
String Msg="";
if (request.getParameter("Name")!=null)
{
    No=request.getParameter("No");
    Name=request.getParameter("Name");
    Lesson=request.getParameter("Lesson");
    String SQL="SELECT * From 成绩单";
    SQL=SQL+" Where 学号="+"'"+No+"'"+"And 姓名="+"'"+Name+"'";
    Connection conn=null;
    Statement stmt=null;
    ResultSet rsScore=null;
    try{
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        }
    catch(ClassNotFoundException ce){
          out.println(ce.getMessage());
         }
    try{
        conn=DriverManager.getConnection("jdbc:odbc:test");
        stmt=conn.createStatement();
        rsScore=stmt.executeQuery(SQL);
       }
    catch(SQLException e){
          System.out.println(e.getMessage());
         }
    if(!rsScore.next())
      {
         Msg="你不是合法考生";
      }
    else
    {
         if(rsScore.getInt(Lesson)!=-1)
         {
             Msg="你已经考过本科目了";
         }
         else
         {
     response.sendRedirect("test.jsp?Lesson="+Lesson+"&Name="+Name+"&No="+No);
         }
      }
  }
       %>
 <HTML>
 <meta HTTP-EQUIV="Content-type" content="text/html;charset=gb2312">
 <BODY BGCOLOR="BEIGE">
   <H1 ALIGN="CENTER">在线考试系统</H1>
   <HR>
       <FORM ACTION="login.jsp"METHOD="post">
            <P>考试科目:<SELECT NAME="Lesson"SIZE="1">
                <OPTION VALUE="JSP">JSP</OPTION>
                <OPTION VALUE="XML">XML</OPTION>
            </SELECT></P>
   <P>姓名:<INPUT TYPE="TEXT" NAME="Name" VALUE="<%=Name%>"></P>
   <P>学号:<INPUT TYPE="TEXT" NAME="No" VALUE="<%=No%>"></P>
      <P><INPUT TYPE="SUBMIT" NAME="SEND" VALUE="开始考试"></P>
      </FORM>
      <HR>
      <FONT Color="red"><%=Msg%></FONT>
 </BODY>
</HTML>      
      
它会提交到test.jsp 代码如下:<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.sql.*"%>
<%
 
request.setCharacterEncoding("utf-8");
String No="";
String Name="";
String Lesson="";
String Msg="";
if (request.getParameter("Name")!=null)
{
    No=request.getParameter("No");
    Name=request.getParameter("Name");
    Lesson=request.getParameter("Lesson");
    String SQL="SELECT * From 成绩单";
    SQL=SQL+" Where 学号="+"'"+No+"'"+"And 姓名="+"'"+Name+"'";
    Connection conn=null;
    Statement stmt=null;
    ResultSet rsScore=null;
    try{
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        }
    catch(ClassNotFoundException ce){
          out.println(ce.getMessage());
         }
    try{
        conn=DriverManager.getConnection("jdbc:odbc:test");
        stmt=conn.createStatement();
        rsScore=stmt.executeQuery(SQL);
       }
    catch(SQLException e){
          System.out.println(e.getMessage());
         }
    if(!rsScore.next())
      {
         Msg="你不是合法考生";
      }
    else
    {
         if(rsScore.getInt(Lesson)!=-1)
         {
             Msg="你已经考过本科目了";
         }
         else
         {
     response.sendRedirect("test.jsp?Lesson="+Lesson+"&Name="+Name+"&No="+No);
         }
      }
  }
       %>
 <HTML>
 <meta HTTP-EQUIV="Content-type" content="text/html;charset=gb2312">
 <BODY BGCOLOR="BEIGE">
   <H1 ALIGN="CENTER">在线考试系统</H1>
   <HR>
       <FORM ACTION="login.jsp"METHOD="post">
            <P>考试科目:<SELECT NAME="Lesson"SIZE="1">
                <OPTION VALUE="JSP">JSP</OPTION>
                <OPTION VALUE="XML">XML</OPTION>
            </SELECT></P>
   <P>姓名:<INPUT TYPE="TEXT" NAME="Name" VALUE="<%=Name%>"></P>
   <P>学号:<INPUT TYPE="TEXT" NAME="No" VALUE="<%=No%>"></P>
      <P><INPUT TYPE="SUBMIT" NAME="SEND" VALUE="开始考试"></P>
      </FORM>
      <HR>
      <FONT Color="red"><%=Msg%></FONT>
 </BODY>
</HTML>