Hi
As the DS has no regional coding, games and consoles from all countries will work together. However in the case of a Japanese game be aware that they use a different alphabet and charater set, so your game will work it's just any on screen instrustions will be in Japanese.
BTW don1901 'pal' refers to the colour tv system, so has no relevance in the case of a handheld console as it uses it's own proprietry display.
Lots of info here, your query is answed in 3.5 Regional Division
http://en.wikipedia.org/wiki/Nintendo_ds