using laptop charger

[NoiseEHC]

Hi!

I am thinking about using my laptop's charger instead of the OLPC 
charger in the future as I move a lot and it's getting really tiresome 
to bring both chargers with me. The plan is to create a converter plug 
and use only the laptop's but it has different voltage levels.

laptop: TOSHIBA
part: PA3715U-1ACA
model: PA-1750-24
output: 19V - 3.95A

XO-1.75: DARFON
model: BBOJ-C
output: 13.5V - 1.85A

So can I plug my XO to the TOSHIBA adapter? The page says that 11-18V 
needed, while the laptop's is 19V. Shall I use a resistor to drop the 
voltage or is it unnecessary? Power usage is not an issue to me. (BTW I 
will use the plug from the XO-1's charger, I guess that it did not 
change in the meantime.)

Thanks,
Andrew