Problems with the login. ¿Can you help me?

I create a NCSoft account and when i go to de login menu on the game (Lineage II) that says "username of password incorrect". So, i think i have to "Add Game" in the NCSoft account page but it doesn't appear.
Where can i "Add Game" for Lineage II, or what i'm doing wrong?
If somebody can help me, i appreciate that, im from Venezuela and sorry if i had bad english.
:)