[求助]JSP连接数据库SQL Server2000问题

exception

javax.servlet.ServletException: [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.
	org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:825)
	org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
	org.apache.jsp.ch9._1_jsp._jspService(_1_jsp.java:86)
	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)

root cause

java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.
	com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
	com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
	com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
	com.microsoft.jdbc.sqlserver.tds.TDSConnection.<init>(Unknown Source)
	com.microsoft.jdbc.sqlserver.SQLServerImplConnection.open(Unknown Source)
	com.microsoft.jdbc.base.BaseConnection.getNewImplConnection(Unknown Source)
	com.microsoft.jdbc.base.BaseConnection.open(Unknown Source)
	com.microsoft.jdbc.base.BaseDriver.connect(Unknown Source)
	java.sql.DriverManager.getConnection(DriverManager.java:512)
	java.sql.DriverManager.getConnection(DriverManager.java:171)
	org.apache.jsp.ch9._1_jsp._jspService(_1_jsp.java:52)
	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)
请问这是怎么回事？
我的jdk目录为C:\j2sdk1.4.2_05
    tomcat目录为C:\Tomcat 5.0
    数据库目录为C:\Program Files\Microsoft SQL Server
    驱动目录为C:\Program Files\Microsoft SQL Server 2000 Driver for JDBC
    并把C:\Program Files\Microsoft SQL Server 2000 Driver for JDBC\lib下的三个包拷贝到了
        C:\Tomcat 5.0\common\lib下，并在环境变量里的CLASSPATH下添加了这三个包
    请高手帮忙