Using Debian Squeeze.
I did a silly thing!!
Was getting an error message related to libgtk, and I uninstalled libcanberra0 package. Doing this removed my gnome completely!!
Next time I boot, I get command line. I installed gnome from cmd line.
I can login into the desktop, but now it is painfully extremely slow.
When I move my mouse over icons, it lags and when I type any character, it takes literally a second to appear!! Browsing with Google Chrome is nearly impossible!! However mouse movement is more fluid if I don't hover over any icons, menus.
And I have to work on a GUI for my project, and my time is limited!!
Please help!! Thanks.

the problem got fixed, but I don't know how!!
I removed x-window-system, xorg, gdm3, gnome and reinstalled them.
I know this is highly amateurish!!
Still, I would appreciate if anybody could tell me what was the problem; can save me all the troubles in future!!

I don't know what the problem was, but to save you troubles in the future:
1. If this is your production system don't play around with it. If you have to play around make a backup first.
2. Always read the screen output, this could have saved you the time for troubleshooting.
3. If you don't understand what exactly will happen when you confirm a question, ask here first, not after confirming.
4. Can't say it often enough: Backup, Backup, Backup, especially when this is a production system. This is the point many people simply omit, but that is the worst idea ever.

Thanks
Will definitely take that into consideration; part of my learning curve!!
I gambled only because it was kinda new installation.