java jdbc连接SQL server2008数据库有关问题！多谢

package com.text;import javax.swing.*;import java.awt.*;import java.util.*;import java.sql.*;import java.awt.event.*;public class text1 extends JFrame{     Vector rowDate,columnNames;     JTable jt=null;     JScrollPane jsp=null;     //定义数据库需要的     PreparedStatement ps=null;     Connection ct=null;     ResultSet rs=null;    public static void main(String[] args) {    text1 tt=new text1();        }        public text1()    {        columnNames=new Vector();        columnNames.add("学号");        columnNames.add("姓名");        columnNames.add("性别");        columnNames.add("年龄");        columnNames.add("籍贯");        columnNames.add("门派");                rowDate=new Vector();        System.out.println("ok1");        try {            //加载驱动            Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");            ct=DriverManager.getConnection("jdbc:microsoft:sqlserver://127.0.0.1:1433;databaseName=stuText");            ps=ct.prepareStatement("select * from stu");            rs=ps.executeQuery();            System.out.println("ok2");            while(rs.next())            {                Vector hang=new Vector();                hang.add(rs.getString(1));                hang.add(rs.getString(2));                hang.add(rs.getString(3));                hang.add(rs.getInt(4));                hang.add(rs.getString(5));                hang.add(rs.getString(6));                rowDate.add(hang);            }        } catch (Exception e) {            // TODO: handle exception            e.printStackTrace();        }finally        {            try {                if(rs!=null)                {                    rs.close();                }                if(ps!=null) ps.close();                if(ct!=null) ct.close();            } catch (Exception e2) {                // TODO: handle exception                e2.printStackTrace();            }        }        System.out.println("ok3");        jt=new JTable(rowDate,columnNames);        jsp=new JScrollPane(jt);        this.add(jsp);        this.setSize(400, 300);        this.setVisible(true);        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);            }}

java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver    at java.net.URLClassLoader$1.run(Unknown Source)    at java.security.AccessController.doPrivileged(Native Method)    at java.net.URLClassLoader.findClass(Unknown Source)    at java.lang.ClassLoader.loadClass(Unknown Source)    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)    at java.lang.ClassLoader.loadClass(Unknown Source)    at java.lang.ClassLoader.loadClassInternal(Unknown Source)    at java.lang.Class.forName0(Native Method)    at java.lang.Class.forName(Unknown Source)    at com.text.text1.<init>(text1.java:35)    at com.text.text1.main(text1.java:17)