How to check for internet connectivity and download file?

[Tyro]

I've used Burton Radons' "urllib" in the past to get download files from the internet, however the library has atrophied and can no longer be used with DMD v2.029 (not how long it's been this way because I haven't tried to compile it since 2006).

I'm wondering if someone could point me to an example of how to check for internet connectivity and if available download the latest version of a given file.

Thanks in advance.
Andrew