problem after upgrading to ubuntu 11.04 from 10.10

I upgraded my ubuntu 10.10 to ubuntu 11.04 via update manager. during upgradation there were some error messages which I ignored. now I don't see the left bar from where i could open the browser, evolution mail client, file manager etc. also the top right side functions like network manager, sound control, date-time etc. are gone. only 'docky' application which was earlier installed in v 10.10 is visible and operational.
kindly help me resolve this problem.
thanks