What internet site can I find financial statements of businesses in Chicago?

I am trying to gather a list of mid-sized businesses in chicago according to their cash flows and net income. I was told there was a site that you can obtain all information about businesses in particular area. Does anyone know anything about this?

Answer:
If they are publicly held companies on the NYSE, you can go type the stock symbol into any business web search engine and it will pop up. If they aren't public, they usually won't release that information unless you are a creditor or subscribe to the Dun and Bradstreet reports.
You may be better off going to your public library and accessing some of the electronic databases. Librarian should be able to help you