Connection Failed

Hi,

When user tried to connect to sql server, gets following error:

SQLState '28000'
SQL Server Error: 18456
Micorsoft SQL Server Native Client 10.0 SQL Server login faile for user abc\xyz.
Connection failed:
SQLState '42000'
SQL Server Error: 4064
Micorosft SQL server Native Client 10.0 SQL Server cannot open user default database. Login failed.

How to resolve this issue, please help.

Thanks