[Lazarus] How to find out the public IP in code?

[Bo Berglund]

I would like to be able to find out the public IP address of the Pi in
a Lazarus program.
How can this be accomplished?
It is either connected to a wired or WiFi network router.
in my browser I can go to http://checkip.dyndns.com/ and it will print
a message with my IP address.
But how is this done in code?

-- 
Bo Berglund
Developer in Sweden