how to get historic P/E data

where do i get data for 10 years or more regarding a company's P/E
For example, I want to know P/E of Infy from 2001 to 2011 (any month)

do search in NSE

Here is the indices historical PE................

http://www.nseindia.com/products/content/equities/indices/historical_pepb.htm

I want for a company and not for an index

Did you try Annual report of Infy. You shd be able to get them from Infy's site. Each annual report will have Earnings of previous few quarters.