Hi there praveen33,
I would agree with kanewolf. You need to back up the data stored on the drive ASAP.
As for fixing it, I would say that in most cases, the drive should be replaced as it con't really be fixed.
You can test the drive with one of these:
http://www.tomshardware.co.uk/forum/282651-32-best-diagnostic-testing-utility
Just upload a screenshot of the SMART report to an image hosting website and post the link over here.
The SMART data should give us more detailed view on what is wrong with the drive.
Cheers,
D_Know_WD