Set / clear windows proxy via command line

It is a very common task to set and clear the proxy setting depending on the client's network configuration. I was frustrated going through Tools-->Internet options-->Connections tab-->LAN settings and configuring the proxy settings so I ended up having a couple of batch scripts that set the client's proxy and one to reset the settings when I am in a more relaxed environment where traffic passes through the normal gateway... Note that I have created shortcuts and set them to "Run as administrator" as the following commands require elevation.