jb连sql server时出现问题,帮我看下好吗

我用的JDBC驱动直连,环境变量设完,测试代码如下:
import java.sql.*;
class Test{//本程序在jdk1.4.2下调试通过.
    public static void main(String args[])
    {
        String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=网络选课";
        String user ="sa";//这里替换成你自已的数据库用户名
        String password = "sa";//这里替换成你自已的数据库用户密码
        String sqlStr = "select CourseID, CourseName, CourseStyle from Course";        try{    //这里的异常处理语句是必需的.否则不能通过编译!    
            Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
            System.out.println( "类实例化成功!" );            Connection con = DriverManager.getConnection( url, user, password );
            System.out.println( "创建连接对像成功!" );            Statement st = con.createStatement();
            System.out.println( "创建Statement成功!" );            ResultSet rs = st.executeQuery( sqlStr );
            System.out.println( "操作数据表成功!" );
            System.out.println( "----------------!" );            while(rs.next())
            {
                System.out.print(rs.getString("CourseID") + "    ");
                System.out.print(rs.getString("CourseName") + "    ");
                System.out.println(rs.getString("CourseStyle"));
            }
            rs.close();
            st.close();
            con.close();
        }
        catch(Exception err){
            err.printStackTrace(System.out);
        }
    }
}然后运行后出现下列信息:类实例化成功!
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSConnection.<init>(Unknown Source)
at com.microsoft.jdbc.sqlserver.SQLServerImplConnection.open(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.getNewImplConnection(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.open(Unknown Source)
at com.microsoft.jdbc.base.BaseDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:525)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at Test.main(Test.java:14)