~Milotic~ said:
you need to:
obtain the ruby and sapphire and give it to celio
defeat elite four in both games
get the national dex in both games
No, you don't. This is a mixup between Ruby/Sapphire and Emerald that I've seen all too often on these forums.
All you need to do to trade between Ruby/Sapphire and Fire Red/Leaf Green is get the Network Machine on One Island to Link Level 2 by giving Celio the Ruby and the Sapphire in your Pokemon Fire Red/Leaf Green game. Once you trade a Pokemon that is not in the Hoenn Dex to your Pokemon Ruby/Sapphire game, your Pokedex in Pokemon Ruby/Sapphire will upgrade to a National Pokedex.
In Emerald, as well as upgrading the Network Machine in Fire Red/Leaf Green, you must also get the National Pokedex in Emerald from Professor Birch after you defeat the Elite Four in order to be able to trade between Emerald and Fire Red/Leaf Green.
PlusleMinun, since you have Sapphire and Leaf Green, you seem to have fulfilled all the conditions necessary to trade in between the two games. I can only assume that your Link Cable may be faulty, or if you're trying to trade using the Wireless Adapter, it won't work because the Wireless Adapter is incompatible with Pokemon Ruby/Sapphire.