JDBC联接数据库不成功

.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]用户 'sa' 登录失败。
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processErrorToken(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processReplyToken(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSLoginRequest.processReplyToken(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processReply(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)
这是错误信息，是怎么事啊，我的数据库应该没有问题，可是就是联不上啊，请各位高手们指点下。。。