I have a asus X51RLseries. Its 256mb vga. Can i upgrade it to 1gb or 2gb?

Solution
Main Memory DDR2 667 MHz SDRAM, 2 x SODIMM socket for expansion up to 2GB SDRAM
https://www.asus.com/Notebooks/X51RL/specifications/
check in the bios to see if can adjust amount of ram for videocard.