Affordable wedding reception in Chicago?

Where in Chicago or surrounding suburbs can we host a wedding reception without putting ourselves in debt? We are expecting about 100 people about 20 of which are children under the age of 12. The wedding and reception will be held on Friday June 22, 2012. The date is so far away because we want to make sure that we have enough money to cover all of the expenses. Our budget is about $4,100 as of now. I've noticed that some places do in fact offer discounts if you hold your event on a weekday or Friday and Sunday. We chose a Friday. We would also like a place that offers discounted prices for children. We are looking really hard but whenever we find a place of interest something always ends up being wrong. Please if anyone has any suggestions let us know. We are in dire need of help.