"Cancelled" or "Canceled?"

Which is it? One el or two? I'm usually a darn fine speller but I can't figure this one out. The dictionary hasn't been helpful. (I say two els). I've always used cancelled. I always put "define cancelled" (or whatever word) into google when I'm in doubt. It will correct the spelling and come up with the definition. 'cancelled' and 'canceled' came up with different definitions. "Cancelled" being "

[kk6]

ふとどっちが正しいのか気になって調べてみたら、アメリカ人とイギリス人が戦ってた。その二国にとどまらず色んな国の色んな視点から考察してて面白い。

[kiyo_hiko]

Canceled? Weird spelling!と自分も思って調べてみたら両方正しいなんていってる人もいるし、colorとcolourだとか、こんにちわとこんにちはみたいなものなんだろうか？

[pho]

lは１つでも２つでもいいのか。でも２つがいいな。

[rna]

Cancelled か Canceled か問題。