I need to get ride of a lot flies.?

In my basement and in on my main floor, I have a lot of flies. Me and my friends killed about 15 with flyswatters. But I wanna get ride of them. I think 1 got in and then spawned others. So I want to get rid of them fast and efficiently. Thank you in advance.I need to get ride of a lot flies.?
Ok now...Flies are born of maggots....So , where's the maggot bed in the house ? The basement is probably the place you need to look. Is there standing water any where from a leak down there ? Any dead rodents down there ? Or they are coming from outside , so if the screens have holes in them put a patch on them. If they are comming from outside find out from where. Maybe the trash cans need to be cleaned out with bleach.Good luck.I need to get ride of a lot flies.?
Check your basement and see if you have an open sewer drain. If you locate it, pour bleach down it. (This will help with any odor also). Go to Home Depot and buy flycatcher strips and hang them. Should take care of the problem. Also, don't leave any open food or fresh food out on your counters. And put dirty dishes in the dishwasher immediately or wash them right away. They are searching for food sources...
get zip lock baggies and put a penny in them then fill w/ water and hang around the room, it works but not sure how exactly
Use hairspray and a lighter XD home made flamethrower, that should work!
Sticky fly traps.