I'm stuck in Soul Silver?

I've beat all the gyms in Johto, beaten the elite 4, caught entei raiku and suicune, and I've gotten the Cerulean, Saffron, Celadon, Vermilion and Fuchsia badges and I just fixed the power plant. I dont know what to do. When I try to go into the radio tower on Kanto there's a guy there that wont let me go up the elevator. Please help, I don't know what to do.