i just wikipediad it and it says that luigis his younger brother,but it doesnt mention his age

Wait, TWINS?

Awesome.  I still haven't played that yet, but it's great to hear it has moustache jokes.  I think every single new boss in the DS remake of Mario 64 had a giant moustache and commented on the moustaches of Mario, Luigi, and Wario.  And there are tons of moustache jokes in the Mario and Luigi RPGs on GBA and DS.

The cartoons always had Mario as the older brother.

Also, their last names are Mario so their names are Mario Mario and Luigi Mario.  This is also why they're known as "The Mario Bros."

I remember, in the 90's cartoon, Mario calls Luigi his "BIG, little brother", and Luigi would call Mario his "Little, big brother".

What I'm trying to say is........Sony stole Little Big Planet from Nintendo!!

In Yoshi's Island they are twins. I didn't hear anything about Mario being the older brother until I watched the Mario cartoons, but what would they prove?

so where do waluigi and wario fit into this? are they both younger thean mario and luigi?

That's a good question that.

Wario was a childhood acquaintance of Mario.  Basically all of Wario's antics are him trying to get revenge on Mario for Mario being mean to him while they were growing up... or something like that.

According to the Super Mario Adventures and Mario vs. Wario comics, Wario is a childhood rival of Mario's.

According to Nintendo Power, Wario is a cousin of Mario and Luigi.

According to the Colonel from MGS, when telling Snake about Wario in Brawl, Wario was a rival of Mario's.

But I don't think any of those are canon. If Yoshi's Island DS is canon, then Mario, Luigi, and Wario were all born at the same time, along with Donkey Kong and Peach.