Security Error while using SQL 2005

Hello,
I'm using SQL server 2005 through the java code to connect to my database.
When i try to connect I see the following error:
com.microsoft.sqlserver.jdbc.SQLServerException: The server principal "XXXX" is
not able to access the database "YYYY" under the current security context.
at com.microsoft.sqlserver.jdbc.SQLServerException.ma keFromDatabaseErro
(Unknown Source)
at com.microsoft.sqlserver.jdbc.IOBuffer.processPacke ts(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.se ndExecute(Unknown
ource)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.do ExecuteQuery(Unkno
n Source)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStat ement.executeQuery
Unknown Source)

Help me solving this.

Thank you,
Regards,
Prakash

Have you looked that error up?
I'm sure the Microsoft site will have something on it.