2 Questions regarding expansions

First of all, I have the original Guild Wars and I am thinking about buying either Factions or Nightfall.

My question is that if I buy Nightfall, will I get all the stuff from Factions like the Assassin Class or do I have to buy both Nightfall and Factions?

My second question is if Nightfall and Factions are Expansion packs, how exactly do I use them? Do I just install it?

Thank You

for first question: Yes you have to buy Factions to get all the factions stuff

for second question: you get a cd key with your purchase of the game. You type in the cd key and connect it to your account

just be sure to add it to your existing account.

thank you

Factions gives you access to Cantha and the Assassin and the Ritualist classes(among other things). Nightfall gives you acces to Elona and the Dervish and the Paragon classes(among other things). On the login screen, there is a button that says, "Add CD Key", you click on that and just type in the Nightfall or Factions CD key and it updates your account. Your existing characters can access the new continents via very simple quests in Lion's Arch.

You can buy Factions and/or Nightfall with a credit card from the Guild Wars Store which is in the top right corner of the character selection screen. It will automatically update your account upon purchase.

Also you don't have to install anything, the game will update it's self when you login after adding the new key(s)

and they are not expansions....they are 'standalone' chapters. This means you can play any of them without having the others, though you wouldnot be able to access things from the other chapters eg: no dervish if you have just factions--but you can play/create any of the 6 core classes in any/all of the chapters.

Gw:en that is set to be released later this year IS an expansion and will require you to have ONE of the chapters to add it on.