[filiadragongurl]

I'm guessing you're aiming for "nani yattenno" which is slang-ish for "nani yatte iru no" (at least that's my understanding). So anyway, "nani yatte iru no" means "what are you doing?" I also think that this phrase is usually used in the sense that someone just did something stupid and someone says "*what* are you *doing*?!?!" Of course that all depends on context and the manner in which the person says it...

Is that what you were going for?