用Tomcat调试jsp程序出现如下：“ userName cannot be resolved” 是怎么回事，请高手帮帮忙阿，急
代码如下
<%@ page language="java" import="java.sql.*" %>

String userName = request.getParameter("userName");
String userPwd = request.getParameter("userPwd");
String userAge = request.getParameter("userAge");
String userID = request.getParameter("userID");
<%
String sql = "";

sql = "insert into table_user(";
sql += "userName,userPwd,userAge,userID";
sql += ") values (";
sql += "'" + userName + "',";
sql += "'" + userPwd + "',";
sql += "'" + userAge + "',";
sql += "'" + userID + "'";
sql += ")";

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn = DriverManager.getConnection("jdbc:odbc:db","","");
Statement stmt = conn.createStatement();
stmt.executeUpdate(sql);


conn.close();
%>





[解决办法]
应该是这样的：

<%@ page language="java" import="java.sql.*" %>

<%
String userName = request.getParameter("userName");
String userPwd = request.getParameter("userPwd");
String userAge = request.getParameter("userAge");
String userID = request.getParameter("userID");

String sql = "";

sql = "insert into table_user(";
sql += "userName,userPwd,userAge,userID";
sql += ") values (";
sql += "'" + userName + "',";
sql += "'" + userPwd + "',";
sql += "'" + userAge + "',";
sql += "'" + userID + "'";
sql += ")";

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn = DriverManager.getConnection("jdbc:odbc:db","","");
Statement stmt = conn.createStatement();
stmt.executeUpdate(sql);


conn.close();
%>