再补充一下，我是在使用后台的管理员登录时，当输入用户名和密码后出现的错误。我看了一下我的项目文件夹，在光盘给的整个文件夹的WEB-INF/classes文件夹下有各个JavaBean的class文件，但是当我把整个文件夹拷到MyEclipse里面，对整个项目进行clean后，classes文件夹下的class文件就全部消失了，请问这是怎么回事啊？谢谢

呃，不好意思，现在又遇到新问题了，我按照word文档上说的过程又重新配置了一下我的web应用程序，结果还是在后台管理员登陆那里出问题了，而且问题更多，基本上都是关于数据库连接的。还想麻烦高手给解答一下。下面是报错的信息：
select * from tb_usertable where name='TSoft'and password='111'
[font color=#0000FF]org.apache.tomcat.dbcp.dbcp.SQLNestedException[/font]: [font color=#FF0000]Cannot create JDBC driver of class 'com.microsoft.jdbc.sqlserver.SQLServerDriver' for connect URL 'jdbc:microsoft:sqlserver//localhost:1433;databasename=db_net'
[/font] at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1452)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1371)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
at com.wsy.connsqlserver.getConnection(connsqlserver.java:28)
at com.wsy.connsqlserver.executeQuery(connsqlserver.java:40)
at com.wsy.selectsql.check(selectsql.java:47)
at org.apache.jsp.houtai.houtaitest_jsp._jspService(houtaitest_jsp.java:88)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
Caused by: [font color=#0000FF]java.sql.SQLException[/font]: No suitable driver
at java.sql.DriverManager.getDriver(DriverManager.java:264)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1437)
... 27 more
java.lang.NullPointerException
at com.wsy.connsqlserver.executeQuery(connsqlserver.java:42)
at com.wsy.selectsql.check(selectsql.java:47)
at org.apache.jsp.houtai.houtaitest_jsp._jspService(houtaitest_jsp.java:88)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
其中第二个给我提示说没有合适的驱动，可是我同学也是用的SQL Server 2000，我的数据库驱动也是从他那里拷过来的，而且在他的机器上就可以正常运行，应该不会有问题的。所以非常想让高手给我解决一下。谢谢了

  除了要添加连接数据库的驱动外，还要将光盘中附带的数据库文件附加到你本地的数据库中。