Catch Eevee How Do You Catch Eevee On Diamond With Out Beating The Elite Four?

How do you catch eevee on diamond with out beating the elite four? - catch eevee

I keep hearing that you have an Eevee in the diamond-git, but you have to beat the elite four. I'm not going to the elite, beat the four
one Glaceon, but I found nothing and I hear if you go pookemon Mansion and talk with the owner who is out too. Go back and he will have a Pokémon that inhabit the site to tell today. satnds but only there and say the same thing I did not ant Rilly gos its sooo want an Eevee!
anoying to read the same thing and UHG !!!!!!!!!!!!!! So tell me how to git one Eevee beat the elite four and I want to make a trade soon