Please help .. Dell Latitude D410 Memory Type

Hi Guys, this is an old work machine with 1 Gb RAM. Does anyone know what type of RAM I should get from a computer store to get this up to 3 or 4 Gb?

From http://support.ap.dell.com/support/edocs/systems/latD410/en/sm/upgrade0.htm#wp999869, I know it takes 2 DDR2 DIMM modules ...

1) do the 2 dimms have to be the same size? If not, I would like to get a 2 Gb dimm and place that the second slot for a total of 3 Gb.
2) is that all I need to know specify when buying the memory, that it's DDR2 dimm for notebooks? are there other specs like speed / latency?

 

Oh, never mind. Found the specs for hte machine. It only takes a maximum of 2 Gb. Sigh.