Reconnect to network automatically?

Is there a utility that will reconnect a mac to it's wireless network when it falls off that network?

My iMac is out back in our converted garage, where it serves up music to all the expresses in the main house from a large hard drive. The airport extreme is in the main house, because that's where the cable for the FIOS is. Not the best arrangement, but kind of just the way it needs to be.

The iMac keeps falling off the network, pretty much once a day if not more. Wireless phone interference and other things are the problem I'm assuming. I could run a cable out there, but I'd rather not.

When I just went out there to reconnect to the network, it dawned on me that all the networks were available, (neighbors networks, my network) it's just that my network wasn't chosen, so there was no connection. So it dawned on me, does anyone make a utility that will reconnect a mac to a network when any time that network becomes available? Seems like a simple thing???

 

Yes, it's dropping out for some reason, probably the one you stated. Ny question is why, if it's supposed to automatically connect, is it not doing that?When I go to reconnect it, the network is always sitting there and available. Why doesn't it reconnect by itself?