This is the request you tell the server.
POST /IpLocator.htm?GetLocation HTTP/1.1
Note: Some webservers need more information than this, read up on the Hypertext Transfer Protocol and add them
Ok, anyways ...
POST is just post request, telling the server what page you want, and HTTP version.
Host is needed for 1.1, and the fact that most sites use that to redirect to the correct site (if they have many Domains on one IP/Computer)
Content-Length is the length in BYTES for the post data. (you can use $len to calculate this)
Note that the EMPTYLINE is needed (after Content-Length and before the postdata)
PS: I haven't tested this, it should work.
But even if it doesn't work you should be able to fix it reading up on the protocol.