about different version of guild wars

how does you enter different servers? i mean the servers of different regions like korean servers, european servers, etc, etc. If i buy the guild wars UK version, does it mean that i stick to european server? If yes, how can i change server to american server??Thx for reply

You are allowed 5 changes as far as I know.
From EU to US and back and forth.
I don't think you can change to Korea though as someone mentioned somewhere before.

how do i make the changes??

Look at one of the first screens when you start the game. You should find some sort of sub menu to go into. Just click around. You will eventually find some way to switch your server, maybe its in your account information? Just look in the first few screens before you choose which character you wish to play.

Somewhere before you choose your character and start playing.
I think its under account options.