One of the international airports of the state is the O'Hare International Airport.

This airport is located in the northwest corner of the state, 17-kilo meters from the Chicago Loop. The airport serves as a hub for both the United Airlines as well as the American Airlines. The airport gets operated by the Chicago City aviation Department.

The airport had over 881,566 flights in 2008. This included 64 percent commercial fliers, 33 percent air taxi, 3 percent general aviation and less that one percent of military aircraft fliers. This accounted to over 2409 fights a day, more than any other average airport.

The airport is the second busiest in the world as of now. The airport is very active internationally with flights to over 60 countries of the world. The airport ranked fourth among all its continent compatriots for most international gateways.

The airport has a reputation of getting voted the best airport in the United States for over ten years.

Some other facts can be captured from the link:

http://en.wikipedia.org/wiki/O'Hare_International_Airport,

http://www.chicago-ord.com/

http://www.flightstats.com/go/Airport/airportDetails.do?airportCode=ORD

All individuals, corporations, trusts and estates are required to pay the Illinois Income Tax based on the Federal Internal Revenue Code. To calculate your personal income tax, multiply your net income by a flat rate, which is, at the moment pegged at 3%.

As an individual, you should make estimated tax payments if you own 500$ or more after subtracting the Income tax and other credits for income tax to other states, property tax and others.

If you are not able to file you annual returns by the due date, you date it automatically extended by six months. The income tax return form is Form IL-1040.

For more help you can call the toll (1-800) free numbers.

http://egov.cityofchicago.org/city/webportal/portalContentItemAction.do?contentOID=536913816&contenTypeName=COC_EDITORIAL&topChannelName=Dept&entityName=Budget+%26+Management&deptMainCategoryOID=-536890796&blockName=Budget+%26+Management/Content&context=dept

http://www.superpages.com/yellowpages/C-Income+Tax+Services/S-IL/T-Chicago/