I opened that WEB - http://www.crucial.com/systemscanner/ -and got all the information I needed and even more: explanation on speed which is very important.
I should buy 520 MB or 1GB memory type:DDR memory with support for DDR PC2700 speeds, total up to 2048MB.This is four times bigger than this I have now!
Thank you again! I did not know for this extremely useful sight for memories and now I will recommend it to all my friends.
Dragan from Belgrade,71 years old