HELP ON STOCK MARKET

ANY ONE PLEASE HELP ME FOR KNOWING DATABASE OF ANY COMPANY.

I HAVE PURCHASED SOME PAPER SHARE IN 1995-2000. Still now i have not make any dematerialized for the same share. I want to know that any change in name of the company was there OR Any merger, amalgamation of any company.

I tried to found the base of comapny by  name printed on share certificate but i found most of them were not traded since last somany years.

So there is possibility of amalgamation, merger, demerger or change in the name of the comapny.

Please help me if any one knows how find the database of any company