OK. In this house we have two phone lines. Line one has some problem and is not able to call our ISP, but line 2 can. Therefore line 2 is our Internet line.

Now of course we have the problem with two people wanting to be on at the same time. Therefore Internet connection sharing is a good choice. However, the other computer is not always powered on, and my computer, which could always be on, happens to be a laptop and is not always there. (like when I'm out)

So what I want is software that, when you get on the Internet, checks to see if the other computer has an active connection. If it does, it uses it via the network to connect. If it doesn't, then it starts a connection of its own to be shared should the other want to get on.

The concept is hard to find because everyone is sharing broadband connections, which I can't get here. (except satellite, which is 80 bucks a month - no way.)

Has anyone heard of such a program, and well, since I am a programmer and all, is it technically even possbile to make such a thing?