Frontier Airlines EarlyReturns - Milwaukee or Chicago to Phoenix

I will be going from Milwaukee to Phoenix on March 17th or 18th whichever is cheaper and returning March 27 and was wondering if anyone knew of any good deals out there for one ways, or round trip. I would also be willing to fly out of Chicago. If anyone has any coupon codes or anything like that, that would be of gret help! We are on a tight budget!

Thanks in advance!
Jason

Since this is cross-posted in several other forums, and this isn't specific to Frontier, I'll close this thread.

Regards,
Gary
aka gleff