Hi Mr. Manoj,
As you've already attained your MCSA 2003, you now need to pass exams
70-648 and
70-646 to upgrade your MCSA 2003 to
MCITP: Server Administrator on Windows Server 2008. If you decide to pursue this upgrade, please do so quickly, since exam 70-648 retires on July 31, 2013.
Furthermore, please note that the MCITP: Server Administrator designation also retires on July 31, 2013, to be replaced by the
MCSA: Windows Server 2008 designation. If you certify before July 31, 2013, you'll receive both designations (MCSA 2008 & MCITP:SA), but if you certify after this date, you will only be MCSA: Windows Server 2008.
I hope this information proves useful to you.