MacBook Air A1237 Recovery I replaced the hard drive on my Macbook Air. When I press the option key while powering on it takes me to a screen where I select a WiFi network and nothing else is on the screen. I connect to WiFi and then nothing happens. There Are no other options. What should i do?

I have also tried the same procedure with the old disk, but the same strange thing happens.

It connects to the WiFi network but that's all.
The MacBook Air (from early 2008) does neither have a Recovery HD by default nor an Internet Recovery.  You would need to install the original OS with the medium you received with your computer (Mac OS X 10.5 Leopard) or if you either have the disc or a USB stick version of Mac OS X 10.6 Snow Leopard, you can install that as well (disc version will require either a USB SuperDrive or a second Mac with an optical drive you can share). Once done, you can at least use your computer again already.

If you, however, want to reinstall Mac OS X 10.7 Lion, you will first have 10.6 Snow Leopard installed and fully updated (see above what that will require). Otherwise, you would need a USB stick with the Lion Installer on it to bypass installing Leopard or Snow Leopard.