夜深了还在为关于jsp+tomcat+mysql数据库连接的问题头痛!请高手帮忙

我在tomcat容器编译时DOS中提示 java.lang.ClassNotFoundException
com.mysql.jdbc.Driver
message

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

exception

org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


root cause

java.lang.NullPointerException
org.apache.jsp.first_jsp._jspService(first_jsp.java:98)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.

下面是数据库的连接代码
package com.netshop;

import java.sql.*;

public class OpenDB
{

String userName="root";
String userPassword="123456";
private String driverName = "com.mysql.jdbc.Driver";//"org.gjt.mm.mysql.Driver";(两种加载驱动程序方式都不行)
private String url = "jdbc:mysql://localhost/netshop?useUnicode=true&characterEncoding=gb2312";

Connection dbConn;
public OpenDB()
{

}
public Connection getConnection()
{
try
{
Class.forName(driverName);
dbConn=DriverManager.getConnection(url,userName,userPassword);
}
catch(Exception ex)
{
System.out.println(ex.toString());
dbConn = null;
}

return dbConn;
}

}
MySQL 版本是5.0.21 不知道是不是驱动器的原因还是?如果是的话应该要哪个版本的驱动器,该在哪里存放驱动的什么文件呢? 麻烦武林高手 在这深夜能出手相助,小弟在此感激不尽!