Welcome to SAF, batigol!
The user manual for that laptop is useless in regards to upgrades, but the
Crucial Memory Upgrade site comes through again.
Per that page, there is only one slot in that laptop, so you'll have to remove the original 512 meg. RAM to insert a larger 1 gig. or 2 gig. stick. As it states, the memory is DDR2 PC2-5300 with a maximum of 2GB.